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https://www.readbyqxmd.com/read/29345381/durable-lesion-formation-while-avoiding-esophageal-injury-during-ablation-of-atrial-fibrillation-lessons-learned-from-late-gadolinium-mr-imaging
#1
Mihail G Chelu, Alan K Morris, Eugene G Kholmovski, Jordan B King, Gagandeep Kaur, Michelle A Silver, Joshua E Cates, Frederick T Han, Nassir F Marrouche
INTRODUCTION: Adequate catheter/atrial tissue contact is critical for lesion formation during radiofrequency (RF) ablation of atrial fibrillation (AF). Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) is a unique tool for the evaluation of lesion formation and detection of acute esophageal injury. METHODS: LGE-MRIs were obtained prior, within 24 hours of, and at 115±62 days after first AF ablation in 36 patients. The Visitag module of CARTO3 was used to collect contact force (CF) and duration from a CF sensing ablation catheter for each registered ablation point...
January 18, 2018: Journal of Cardiovascular Electrophysiology
https://www.readbyqxmd.com/read/29344902/occupational-exposure-to-electromagnetic-fields-in-magnetic-resonance-environment-basic-aspects-and-review-of-exposure-assessment-approaches
#2
Valentina Hartwig, Stefania Romeo, Olga Zeni
The purpose of this review is to make a contribution to build a comprehensive knowledge of the main aspects related to the occupational exposure to electromagnetic fields (EMFs) in magnetic resonance imaging (MRI) environments. Information has been obtained from original research papers published in international peer-reviewed journals in the English language and from documents published by governmental bodies and authorities. An overview of the occupational exposure scenarios to static magnetic fields, motion-induced, time-varying magnetic fields, and gradient and radiofrequency fields is provided, together with a summary of the relevant regulation for limiting exposure...
January 18, 2018: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/29344133/improved-treatment-of-early-small-hepatocellular-carcinoma-using-sorafenib-in-combination-with-radiofrequency-ablation
#3
Quanyou Gong, Zhaoxia Qin, Fangli Hou
Small hepatocellular carcinoma is an important leading cause of death amongst cancer patients, our study was designed in order to test the hypothesis that radiofrequency ablation (RFA) combined with a chemotherapeutic drug would improve the outcome for patients. Two groups of patients presenting early small hepatocellular carcinoma were treated with either conventional RFA alone (50 individuals in the control group), or with a combination of RFA and oral sorafenib (40 individuals in an observation group). Individual clinical and laboratory evaluations were done during an average follow-up time of 35 months, and all the data recorded was used to compare results of both treatment approaches...
December 2017: Oncology Letters
https://www.readbyqxmd.com/read/29343977/cost-effectiveness-analysis-of-six-therapies-for-the-treatment-of-lower-urinary-tract-symptoms-due-to-benign-prostatic-hyperplasia
#4
James C Ulchaker, Melissa S Martinson
Objective: To conduct a cost-effectiveness analysis from payers' perspectives of six treatments for lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) and to examine positioning of these modalities in the marketplace for the best use of health care funds and quality-of-life benefits for patients. Methods: The economic analysis was conducted with a Markov model to compare combination prescription drug therapy (ComboRx), minimally invasive therapies (MITs) including convective radiofrequency (RF) water vapor thermal therapy (Rezūm®), conductive RF thermal therapy (Prostiva®), and prostatic urethral lift (UroLift®), and invasive surgical procedures including photovaporization of the prostate (Greenlight® PVP) and transurethral resection of the prostate (TURP)...
2018: ClinicoEconomics and Outcomes Research: CEOR
https://www.readbyqxmd.com/read/29343661/immobilization-technique-for-high-resolution-mr-imaging-of-the-testes
#5
Masayuki Yamaguchi, Hirofumi Fujii
Techniques for testis immobilization can facilitate high-resolution MR imaging applications for testicular diseases by assuring good positioning of the testis on small radiofrequency coils and reducing motion artifacts. We tested negative pressure suction to immobilize the testis of rats during MR image acquisitions. Suction pressure between -5 and -10 kPa assured good positioning, suppressed motion artifacts, and allowed the observation of blood vessels and seminiferous tubules.
January 18, 2018: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/29342992/-radiofrequency-catheter-ablation-of-premature-ventricular-contractions-in-children-under-carto3-system-a-retrospective-study-from-one-single-center
#6
W Ji, J J Wu, Y J Qian, Y W Chen, L J Fu, J Shen, F Li
Objective: To evaluate the clinical effect and summarize the experience of radiofrequency catheter ablation (RFCA) for children suffered from premature ventricular contractions (PVCs). Methods: This retrospective study was conducted by descriptive analysis. A total of 108 cases with frequent PVCs from Shanghai Children's Medical Center were treated with RFCA under the guidance of CARTO3 system from January 2011 to December 2016. The immediate success rate of the procedure, the recurrence rate and the perioperative complications were summarized...
January 2, 2018: Zhonghua Er Ke za Zhi. Chinese Journal of Pediatrics
https://www.readbyqxmd.com/read/29342492/efficacy-and-safety-of-endoscopic-radiofrequency-ablation-for-unresectable-extrahepatic-cholangiocarcinoma-a-randomized-trial
#7
Jianfeng Yang, Jing Wang, Haibin Zhou, Yifeng Zhou, Yang Wang, Hangbin Jin, Qifeng Lou, Xiaofeng Zhang
BACKGROUND:  Endoscopic placement of biliary stents to relieve jaundice is the main palliative treatment for unresectable extrahepatic cholangiocarcinoma. Endoscopic biliary radiofrequency ablation (RFA) has been reported to prolong stent patency, which may be beneficial in improving patient survival. However, available evidence is still insufficient, as most reported studies are retrospective case series. The aim of this study was to explore the clinical effect and safety of RFA in patients with unresectable extrahepatic cholangiocarcinoma...
January 17, 2018: Endoscopy
https://www.readbyqxmd.com/read/29342456/correlation-between-resection-margin-and-disease-recurrence-with-a-restricted-cubic-spline-model-in-patients-with-resected-hepatocellular-carcinoma
#8
Woohyung Lee, Ho-Seong Han, Soyeon Ahn, Yoo-Seok Yoon, Jai Young Cho, YoungRok Choi
BACKGROUND: The relationship between resection margin (RM) and recurrence of resected hepatocellular carcinoma (HCC) is unclear. METHODS: We reviewed clinical data for 419 patients with HCC. The oncologic outcomes were compared between 2 groups of patients classified according to the inflexion point of the restricted cubic spline plot. RESULTS: The patients were divided according to an RM of <1 cm (n = 233; narrow RM group) or ≥1 cm (n = 186; wide RM group)...
January 17, 2018: Digestive Surgery
https://www.readbyqxmd.com/read/29341000/basic-pulse-sequences-in-magnetic-resonance-imaging
#9
Daniel Calle, Teresa Navarro
Magnetic resonance images are obtained by a combination of different radiofrequency pulses and gradient waveforms applied to the subject inside a magnetic field. There are multiple pulse sequences used in clinical and preclinical studies adjusted to whatever physician or researches want to analyze, from basic anatomic images to accurate diagnostic techniques as diffusion, perfusion, or functional imaging. In this chapter, we present the most used radiofrequency pulse combinations of the two groups of sequences available in magnetic resonance imaging: spin-echo and gradient-echo sequences...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29340999/introduction-to-mri-physics
#10
Gary V Martinez
Magnetic resonance imaging (MRI) is an imaging technique derived from radiofrequency (RF) signals of proton that are magnetized by a strong magnetic field. These protons typically originate from water, fat, or metabolites. The application of RF pulses is used to excite the magnetization, whereas pulsed magnetic field gradients are used to provide spatial localization. This chapter describes the fundamental principles giving rise to MR images. Furthermore, the connection between relaxation and image contrast is discussed...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29340935/endoscopic-treatments-of-gerd
#11
REVIEW
Carol Rouphael, Ruthvik Padival, Madhusudhan R Sanaka, Prashanthi N Thota
OPINION STATEMENT: PURPOSE OF REVIEW: Endoscopic therapies for gastroesophageal reflux disease (GERD) are minimally invasive techniques which fill the gap between the medical therapy with proton pump inhibitors (PPIs) and surgical fundoplication. The main endoscopic therapies currently available in the USA are transoral incisionless fundoplication (TIF) using EsophyX device or less commonly, Medigus Ultrasonic Surgical Endostapler, and radiofrequency energy delivery to lower esophageal sphincter using Stretta device...
January 16, 2018: Current Treatment Options in Gastroenterology
https://www.readbyqxmd.com/read/29339752/prognostic-performance-of-ten-liver-function-models-in-patients-with-hepatocellular-carcinoma-undergoing-radiofrequency-ablation
#12
Shu-Yein Ho, Po-Hong Liu, Chia-Yang Hsu, Yi-You Chiou, Chien-Wei Su, Yun-Hsuan Lee, Yi-Hsiang Huang, Fa-Yauh Lee, Ming-Chih Hou, Teh-Ia Huo
Liver functional capacity is a crucial survival determinant for hepatocellular carcinoma (HCC). Noninvasive models were proposed to assess hepatic reserve, but their performance in outcome prediction is unclear. We aimed to investigate 10 currently used liver function models in HCC patients undergoing radiofrequency ablation (RFA). A total 499 HCC patients were prospectively identified. Homogeneity and corrected Akaike information criteria (AICc) were compared. Cox proportional hazards model was used to identify independent survival predictors...
January 16, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29337089/thermal-field-distributions-of-ablative-experiments-using-cyst-mimicking-phantoms-comparison-of-microwave-and-radiofrequency-ablation
#13
Xiao-Wen Huang, Fang Nie, Zeng-Cheng Wa, Hang-Tong Hu, Qing-Xiu Huang, Huan-Ling Guo, Qiao Zheng, Xiao-Yan Xie, Wei Wang, Ming-De Lu
RATIONALE AND OBJECTIVES: The objective of this study was to explore the thermal field distribution of cystic lesions undergoing microwave ablation (MWA) and radiofrequency ablation (RFA) using in vitro phantoms. MATERIALS AND METHODS: Cyst-mimicking lesions filled with sodium chloride (NaCl) solution in acrylamide phantoms were treated with MWA and RFA in vitro. The radiofrequency electrodes or MWA antennas were implanted in the centers of the artificial cystic lesions...
January 11, 2018: Academic Radiology
https://www.readbyqxmd.com/read/29336937/the-combination-of-stereo-eeg-and-radiofrequency-ablation
#14
Hélène Catenoix, Pierre Bourdillon, Marc Guénot, Jean Isnard
SEEG-guided radiofrequency thermocoagulation (SEEG-guided RFTC), a combination of Stereo-electroencephalography (SEEG) and radiofrequency thermocoagulation (RFTC), has been performed since 2001 in drug resistant epilepsy. The interest of this procedure is to aim at total or partial destruction of the epileptogenic zone, as tailored in each individual patient by the SEEG exploration. These multiple SEEG-guided RFTC lesions of epileptic foci are produced by using a radiofrequency generator connected to the electrode contacts...
January 9, 2018: Epilepsy Research
https://www.readbyqxmd.com/read/29336757/radiofrequency-thermal-ablation-heat-energy-transfer-in-an-ex-vivo-model
#15
Shivani Thakur, Sandi Lavito, Elizabeth Grobner, Mark Grobner
Little work has been done to consider the temperature changes and energy transfer that occur in the tissue outside the vein with ultrasound-guided vein ablation therapy. In this experiment, a Ex-Vivo model of the human calf was used to analyze heat transfer and energy degradation in tissue surrounding the vein during endovascular radiofrequency ablation (RFA). A clinical vein ablation protocol was used to determine the tissue temperature distribution in 10 per cent agar gel. Heat energy from the radiofrequency catheter was measured for 140 seconds at fixed points by four thermometer probes placed equidistant radially at 0...
December 1, 2017: American Surgeon
https://www.readbyqxmd.com/read/29335429/rfa-guardian-comprehensive-simulation-of-radiofrequency-ablation-treatment-of-liver-tumors
#16
Philip Voglreiter, Panchatcharam Mariappan, Mika Pollari, Ronan Flanagan, Roberto Blanco Sequeiros, Rupert Horst Portugaller, Jurgen Fütterer, Dieter Schmalstieg, Marina Kolesnik, Michael Moche
The RFA Guardian is a comprehensive application for high-performance patient-specific simulation of radiofrequency ablation of liver tumors. We address a wide range of usage scenarios. These include pre-interventional planning, sampling of the parameter space for uncertainty estimation, treatment evaluation and, in the worst case, failure analysis. The RFA Guardian is the first of its kind that exhibits sufficient performance for simulating treatment outcomes during the intervention. We achieve this by combining a large number of high-performance image processing, biomechanical simulation and visualization techniques into a generalized technical workflow...
January 15, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29334937/perspectives-on-setting-limits-for-rf-contact-currents-a-commentary
#17
REVIEW
Richard A Tell, Christopher A Tell
BACKGROUND: Limits for exposure to radiofrequency (RF) contact currents are specified in the two dominant RF safety standards and guidelines developed by the Institute of Electrical and Electronics Engineers (IEEE) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). These limits are intended to prevent RF burns when contacting RF energized objects caused by high local tissue current densities. We explain what contact currents are and review some history of the relevant limits with an emphasis on so-called "touch" contacts, i...
January 15, 2018: Biomedical Engineering Online
https://www.readbyqxmd.com/read/29334164/clinical-evaluation-of-a-novel-fractional-radiofrequency-device-for-hair-growth-fractional-radiofrequency-for-hair-growth-stimulation
#18
Ines Verner, Torello Lotti
AGA is a common disorder. Different treatments are available to prevent hair loss and achieve hair growth with variable results. The purpose of the present study was to evaluate the efficacy and safety of a novel fractional radiofrequency (RF) device (HairLux, Innogen Technologies Ltd., Yokneam, Israel), to prevent hair loss and induce hair growth. Twenty-five patients received 10 fractional RF treatments every 2 weeks, and were followed up 2 months after the last treatment. All patients were evaluated by global photography...
January 15, 2018: Dermatologic Therapy
https://www.readbyqxmd.com/read/29334130/radiofrequency-ablation-combined-with-multiple-biliary-metal-stent-placement-using-short-type-single-balloon-endoscope-in-patients-with-surgically-altered-anatomy
#19
Tadahisa Inoue, Kiyoaki Ito, Masashi Yoneda
Placement of multiple metal stents (MS) for the management of high-grade malignant hilar biliary obstruction (MHBO) is useful,1,2 and biliary radiofrequency ablation (RFA) has been suggested to improve stent patency.3,4 However, to our knowledge, there are no reports of RFA procedures performed using a single-balloon endoscope (SBE) in patients with surgically altered anatomy. Here, we report a successful case of RFA combined with multiple MS placement using SBE in Roux-en-Y gastrectomy. This article is protected by copyright...
January 15, 2018: Digestive Endoscopy: Official Journal of the Japan Gastroenterological Endoscopy Society
https://www.readbyqxmd.com/read/29333794/ablation-induced-change-in-the-course-of-fascicular-tachycardia
#20
Avishag Laish-Farkash, Avi Sabbag, Michael Glikson, Aharon Glick, Vladimir Khalameizer, Amos Katz, Yoav Michowitz
BACKGROUND: Multiform fascicular tachycardia (FT) was recently described as a ventricular tachycardia (VT) that has a reentrant mechanism using multiple fascicular branches and produces alternate fascicular VT forms. Ablating the respective fascicle may cause a change in the reentrant circuit resulting in a change in morphology. Ablation of the septal fascicle is crucial for successful treatment. OBJECTIVES: To describe four cases of FT in which ablation induced a change in QRS morphologies and aggravated clinical course...
January 2018: Israel Medical Association Journal: IMAJ
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