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https://www.readbyqxmd.com/read/28097733/optimized-amplitude-modulated-multiband-rf-pulse-design
#1
Samy Abo Seada, Anthony N Price, Joseph V Hajnal, Shaihan J Malik
PURPOSE: Multiband pulses are characterized by highly temporally modulated waveforms. Rapid phase or frequency modulation can be extremely demanding on the performance of radiofrequency (RF) pulse generation, which can lead to errors that can be avoided if pulses are restricted to amplitude modulation (AM) only. In this work, three existing multiband pulse design techniques are modified to produce AM waveforms. THEORY AND METHODS: Multiband refocusing pulses were designed using phase optimization, time shifting, and root flipping...
January 17, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28095547/prospective-internally-controlled-blind-reviewed-clinical-evaluation-of-cryolipolysis-combined-with-multipolar-radiofrequency-andvaripulsetechnology-for-enhanced-subject-results-in-circumferential-fat-reduction-and-skin-laxity-of-the-flanks
#2
Julius Few, Michael Gold, Neil Sadick
BACKGROUND: Increasing demand for non-invasive skin tightening and body contouring procedures has led to several technological in- novations in energy-based devices such as ultrasound, radiofrequency and cryolipolysis. An emerging trend in the eld is to evaluate whether combination therapies for skin laxity/body contouring using energy-based devices can deliver superior clinical results and patient satisfaction. As such, the objective of this prospective, internal-controlled, blind clinical study was to assess the safety and efficacy of cryolipolysis followed by multipolar radiofrequency with pulsed electromagnetic elds (PEMF) and adjustable pulsed suction for the treatment of skin laxity in the flanks...
November 1, 2016: Journal of Drugs in Dermatology: JDD
https://www.readbyqxmd.com/read/28093005/cardiac-and-respiratory-effects-of-deep-regional-hyperthermia-using-an-8-mhz-radiofrequency-capacitive-device-on-patients-with-cancer
#3
Rieko Izukura, Hajime Imada, Nobuko Hashiguchi, Hiroyuki Sawatari, Takayuki Ohguri, Mami Miyazono, Shin Ohta, Chizuko Takakura, Keiko Yamasaki, Chie Magota, Kanae Fujita, Hiromi Kuroda, Hideki Hirata, Tomoko Ohkusa, Akiko Chishaki
PURPOSE: Hyperthermia (HT), an adjuvant therapy for variable cancers, may cause physiological changes in the patients, which may lead to cardiovascular problems. Among various HT treatments, the physiological effects of deep regional HT are still unclear. We examined the physiological alterations throughout deep regional HT to improve the HT safety. MATERIALS AND METHODS: Thirty-one patients (age: 61±12 years) with cancer received HT in the thoracic or upper abdominal regions using an 8-MHz radiofrequency-capacitive-device for 50 min...
January 16, 2017: International Journal of Hyperthermia
https://www.readbyqxmd.com/read/28088993/treatment-of-recalcitrant-port-wine-stains-pws-using-a-combined-pulsed-dye-laser-pdl-and-radiofrequency-rf-energy-device
#4
Yoon-Soo Cindy Bae, Hamad Alabdulrazzaq, Jeremy A Brauer, Roy G Geronemus
BACKGROUND: Pulsed dye laser (PDL) is the treatment of choice for port-wine stains (PWS). Some PWS are recalcitrant to this modality. A number of reasons for PDL treatment resistance have been described, including inadequate heat generation. OBJECTIVE: We evaluated PDL combined with radiofrequency (RF) energy into a single device to target larger and deeper blood vessels and overcome PDL resistance. METHOD: This was an open-label, prospective, single-center investigation of a novel device combining RF energy with PDL conducted to treat recalcitrant PWS...
February 2017: Journal of the American Academy of Dermatology
https://www.readbyqxmd.com/read/28074530/slice-profile-and-b1-corrections-in-2d-magnetic-resonance-fingerprinting
#5
Dan Ma, Simone Coppo, Yong Chen, Debra F McGivney, Yun Jiang, Shivani Pahwa, Vikas Gulani, Mark A Griswold
PURPOSE: The goal of this study is to characterize and improve the accuracy of 2D magnetic resonance fingerprinting (MRF) scans in the presence of slice profile (SP) and B1 imperfections, which are two main factors that affect quantitative results in MRF. METHODS: The SP and B1 imperfections are characterized and corrected separately. The SP effect is corrected by simulating the radiofrequency pulse in the dictionary, and the B1 is corrected by acquiring a B1 map using the Bloch-Siegert method before each scan...
January 11, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28072749/ultrasound-guided-pulsed-radiofrequency-treatment-of-the-cervical-sympathetic-chain-for-complex-regional-pain-syndrome-a-retrospective-observational-study
#6
Eung Don Kim, Woo Joo Yoo, Yoo Na Kim, Hue Jung Park
The stellate ganglion is a common target to manage neuropathic pain in the upper extremities. However, the effect duration of a single stellate ganglion block is often temporary. To overcome the short-term effects of a single sympathetic block, pulsed radiofrequency (PRF) can be applied. The aim of the present study was to investigate the efficacy of PRF on the cervical sympathetic chain under ultrasound guidance for complex regional pain syndrome (CRPS).Twelve CRPS patients who underwent PRF on the cervical sympathetic chain were enrolled in this retrospective analysis...
January 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28061002/closed-form-expressions-for-flip-angle-variation-that-maximize-total-signal-in-t1-weighted-rapid-gradient-echo-mri
#7
Matthias Drobnitzky, Uwe Klose
PURPOSE: Magnetization-prepared rapid gradient-echo (MPRAGE) sequences are commonly employed for T1-weighted structural brain imaging. Following a contrast preparation radiofrequency (RF) pulse the data acquisition proceeds under non-equilibrium conditions of the relaxing longitudinal magnetization. Variation of the flip angle can be used to maximize total available signal. Simulated annealing or greedy algorithms have so far been published to numerically solve this problem, with signal to noise ratios optimized for clinical imaging scenarios by adhering to a predefined shape of the signal evolution...
January 6, 2017: Medical Physics
https://www.readbyqxmd.com/read/28034983/radiofrequency-ablation-in-coccydynia-a-case-series-and-comprehensive-evidence-based-review
#8
REVIEW
Yian Chen, Julie H Y Huang-Lionnet, Steven P Cohen
OBJECTIVES: Coccydynia is a condition with a multitude of different causes, characterized by ill-defined management. There are multiple prospective studies, including several controlled trials, that have evaluated conservative therapies. Additionally, a plethora of observational studies have assessed coccygectomy, but few studies have reported results for nonsurgical interventional procedures. In this report, we describe the treatment results of 12 patients who received conventional or pulsed radiofrequency for coccydynia and systematically review the literature on management...
December 29, 2016: Pain Medicine: the Official Journal of the American Academy of Pain Medicine
https://www.readbyqxmd.com/read/28027236/complementary-effects-of-negative-pressure-wound-therapy-and-pulsed-radiofrequency-energy-on-cutaneous-wound-healing-in-diabetic-mice
#9
Bin Chen, Huang-Kai Kao, Ziqing Dong, Zhaohua Jiang, Lifei Guo
BACKGROUND: Negative-pressure wound therapy and pulsed radiofrequency energy are two clinical modalities used to treat soft-tissue wounds. They are purported to affect healing differently. The aim of this experimental study was to contrast the two modalities at a mechanistic level and to investigate whether their combined therapy could achieve additive and complementary effects on wound healing. METHODS: Full-thickness dorsal cutaneous wounds of diabetic, db/db, mice were treated with either negative-pressure wound therapy, pulsed radiofrequency energy, or combined therapies...
January 2017: Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28019035/estimating-and-eliminating-the-excitation-errors-in-bipolar-gradient-composite-excitations-caused-by-radiofrequency-gradient-delay-example-of-bipolar-spokes-pulses-in-parallel-transmission
#10
Desmond H Y Tse, Christopher J Wiggins, Benedikt A Poser
PURPOSE: To eliminate a slice-position-dependent excitation error commonly observed in bipolar-gradient composite excitations such as spokes pulses in parallel transmission. THEORY AND METHODS: An undesired timing delay between subpulses in the composite pulse and their bipolar slice-selective gradient is hypothesized to cause the error. A mathematical model is presented here to relate this mismatch to an induced slice-position-dependent phase difference between the subpulses...
December 26, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28019022/use-of-pattern-recognition-for-unaliasing-simultaneously-acquired-slices-in-simultaneous-multislice-mr-fingerprinting
#11
Yun Jiang, Dan Ma, Himanshu Bhat, Huihui Ye, Stephen F Cauley, Lawrence L Wald, Kawin Setsompop, Mark A Griswold
PURPOSE: The purpose of this study is to accelerate an MR fingerprinting (MRF) acquisition by using a simultaneous multislice method. METHODS: A multiband radiofrequency (RF) pulse was designed to excite two slices with different flip angles and phases. The signals of two slices were driven to be as orthogonal as possible. The mixed and undersampled MRF signal was matched to two dictionaries to retrieve T1 and T2 maps of each slice. Quantitative results from the proposed method were validated with the gold-standard spin echo methods in a phantom...
December 26, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28009767/transient-sensory-recovery-in-stroke-patients-after-pulsed-radiofrequency-electrical-stimulation-on-dorsal-root-ganglia-a-case-series
#12
Seza Apiliogullari, Ilknur A Gezer, Funda Levendoglu
INTRODUCTION: The integrity of the somatosensory system is important for motor recovery and neuroplasticity after strokes. Peripheral stimulation or central stimulation in patients with central nervous system lesions can be an effective modality in improving function and in facilitating neuroplasticity. CASE REPORT: We present 2 hemiplegic cases with sensory motor deficit and the result of the pulsed radiofrequency (PRF) electrical stimulation to the dorsal root ganglia...
January 2017: Neurologist
https://www.readbyqxmd.com/read/27994505/pulsed-radiofrequency-attenuates-diabetic-neuropathic-pain-and-suppresses-formalin-evoked-spinal-glutamate-release-in-rats
#13
Yu-Hsin Huang, Shao-Yun Hou, Jen-Kun Cheng, Chih-Hsien Wu, Chung-Ren Lin
BACKGROUND: Pulsed radiofrequency (PRF) has been used to treat chronic pain for years, but its effectiveness and mechanism in treating diabetic neuropathic pain are still unexplored. The aim of this study was to elucidate the modulation of diabetic neuropathic pain induced by streptozotocin and the release of spinal excitatory amino acids by PRF. METHODS: Diabetes was induced by intraperitoneal administration of streptozotocin. Pulsed radiofrequency was applied to L5 and L6 dorsal roots at 42 °C for 2 min...
2016: International Journal of Medical Sciences
https://www.readbyqxmd.com/read/27990312/ultra-extended-euthermic-pulsed-radiofrequency-for-the-treatment-of-ophthalmic-neuralgia-a-case-report-with-elaboration-of-a-new-technique
#14
Mohinish G Bhatjiwale, Mrudul M Bhatjiwale, Ami Bhagat
BACKGROUND: Pulsed radiofrequency although present for many years has been used little compared to ablative procedures for pain relief. Its use in trigeminal neuralgia is sparse and unreported in the ophthalmic division, where the possibility of sensory loss can lead to high morbidity. We wished to explore the potential of this reportedly safe modality for a prolonged duration in a highly sensitive anatomic neural location, however, in a very secure, structured, and staged manner. CASE DESCRIPTION: A patient suffering from ophthalmic division (V1) medically uncontrolled neuralgia with a preoperative visual analog scale (VAS) score of 9/10 was subjected to a percutaneous pain relief procedure...
2016: Surgical Neurology International
https://www.readbyqxmd.com/read/27964895/spin-locking-of-half-integer-quadrupolar-nuclei-in-nmr-of-solids-the-far-off-resonance-case
#15
Smita Odedra, Stephen Wimperis
Spin-locking of spin I=3/2 and I=5/2 nuclei in the presence of large resonance offsets has been studied using both approximate and exact theoretical approaches and, in the case of I=3/2, experimentally. We show the variety of coherences and population states produced in a far off-resonance spin-locking NMR experiment (one consisting solely of a spin-locking pulse) and how these vary with the radiofrequency field strength and offset frequency. Under magic angle spinning (MAS) conditions and in the "adiabatic limit", these spin-locked states acquire a time dependence...
November 30, 2016: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/27960592/mobile-phone-radiation-induced-perturbation-of-gene-expression-profiling-redox-equilibrium-and-sporadic-apoptosis-control-in-the-ovary-of-drosophila-melanogaster
#16
Areti K Manta, Deppie Papadopoulou, Alexander P Polyzos, Adamantia F Fragopoulou, Aikaterini S Skouroliakou, Dimitris Thanos, Dimitrios J Stravopodis, Lukas H Margaritis
The daily use by people of wireless communication devices has increased exponentially in the last decade, begetting concerns regarding its potential health hazards. Drosophila melanogaster four days-old adult female flies were exposed for 30 min to radiation emitted by a commercial mobile phone at a SAR of 0.15 W/kg and a SAE of 270 J/kg. ROS levels and apoptotic follicles were assayed in parallel with a genome-wide microarrays analysis. ROS cellular contents were found to increase by 1.6-fold (x), immediately after the end of exposure, in follicles of pre-choriogenic stages (germarium - stage 10), while sporadically generated apoptotic follicles (germarium 2b and stages 7-9) presented with an averaged 2x upregulation in their sub-population mass, 4 h after fly's irradiation with mobile device...
December 14, 2016: Fly
https://www.readbyqxmd.com/read/27930554/pulsed-radiofrequency-treatment-of-the-superior-hypogastric-plexus-in-an-interstitial-cystitis-patient-with-chronic-pain-and-symptoms-refractory-to-oral-and-intravesical-medications-and-bladder-hydrodistension-a-case-report
#17
Jong Hae Kim, Eugene Kim, Bong Il Kim
RATIONALE: A variety of therapeutic modalities are available for the treatment of interstitial cystitis. However, among them, the less invasive therapies are usually ineffective, whereas the invasive ones carry potential risks of serious side effects and complications. Pulsed radiofrequency (PRF) treatment of the superior hypogastric plexus may be an alternative to conventional treatments, as it provides nondestructive neuromodulation to the superior hypogastric plexus, which transmits the majority of pain signals from the pelvic viscera...
December 2016: Medicine (Baltimore)
https://www.readbyqxmd.com/read/27924066/assessment-of-atrial-electromechanical-interval-using-echocardiography-after-catheter-ablation-in-patients-with-persistent-atrial-fibrillation
#18
Xiaodong Chen, Minglong Chen, Yingying Wang, Bing Yang, Weizhu Ju, Fengxiang Zhang, Kejiang Cao
We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler (PW) and pulse tissue Doppler imaging (PW-TDI). A total of 25 consecutive in-patients with persistent atrial fibrillation, who restored sinus rhythm after ablation procedure, were recruited in our cardiac center. Echocardiography was performed on each patient at 2 hours, 1 day, 5 days, 1 month and 3 months after the ablation therapy, and atrial electromechanical delay was measured simultaneously by PW and PW-TDI...
November 2016: Journal of Biomedical Research
https://www.readbyqxmd.com/read/27918004/what-devices-to-use-or-not-use-in-skin-of-color
#19
Murad Alam
Lasers and light sources, as well as other energy devices, including radiofrequency, ultrasound, and cold-based therapies, can be used for treatment of aging, dyschromic, or texturally uneven skin. In patients with ethnic skin (ie, skin of color), energy devices are used more cautiously to avoid adverse events. The most common and concerning adverse event is postinflammatory hyperpigmentation. Lower fluence, longer pulse durations, and careful device selection can mitigate the risk of scarring and pigmentary abnormality...
December 2016: Seminars in Cutaneous Medicine and Surgery
https://www.readbyqxmd.com/read/27916509/singlet-order-conversion-and-parahydrogen-induced-hyperpolarization-of-13-c-nuclei-in-near-equivalent-spin-systems
#20
James Eills, Gabriele Stevanato, Christian Bengs, Stefan Glöggler, Stuart J Elliott, Javier Alonso-Valdesueiro, Giuseppe Pileio, Malcolm H Levitt
We have demonstrated two radiofrequency pulse methods which convert the nuclear singlet order of proton spin pairs into the magnetisation of nearby (13)C nuclei. These irradiation schemes work well in the near-equivalence regime of the three-spin system, which applies when the difference in the two (1)H-(13)C couplings is much smaller than the (1)H-(1)H coupling. We use pulse sequences to generate thermally polarized singlet states in a reproducible manner, and study the singlet-to-magnetisation transfer step...
January 2017: Journal of Magnetic Resonance
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