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Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use.

Research Paper Discussions

Pak J Biol Sci . 2008 Apr 15;11(8):1142-6. doi: 10.3923/pjbs.2008.1142.1146. Mercury release from dental amalgam restorations after magnetic resonance imaging and following mobile phone use S M J Mortazavi 1, E Daiee, A Yazdi, K Khiabani, A Kavousi, R Vazirinejad, B Behnejad, M Ghasemi, M Balali Mood Affiliations…

Improved assessment of radiofrequency electromagnetic field power deposition near orthopaedic device using a bone-inclusive ASTM phantom under 1.5T and 3T MRI.

Research RF Safe Research Library Jan 1, 2024

This engineering/simulation study proposes a bone-inclusive ASTM phantom to improve assessment of RF power deposition near orthopaedic implants during 1.5 T and 3 T MRI. Using numerical simulations across multiple implant families, the authors report better correlation of peak 1 g SAR near implants with anatomically…

Helmet Radio Frequency Phased Array Applicators Enhance Thermal Magnetic Resonance of Brain Tumors.

Research RF Safe Research Library Jan 1, 2024

This engineering study describes and simulates a helmet radio-frequency phased array applicator for Thermal Magnetic Resonance (ThermalMR), which combines MRI with targeted RF heating. Using EMF and temperature simulations in a phantom and human head model (including a modeled glioblastoma tumor volume), the authors…

Advanced Radio Frequency Applicators for Thermal Magnetic Resonance Theranostics of Brain Tumors.

Research RF Safe Research Library Jan 1, 2023

This engineering/simulation study evaluates RF applicator array designs for Thermal Magnetic Resonance (ThermalMR), which combines MRI with RF hyperthermia for brain tumor theranostics. Using EMF and temperature simulations at 7.0 T, 9.4 T, and 10.5 T, hybrid loop+SGBT dipole arrays are reported to provide superior…

Structural and Functional Neural Correlates in Individuals with Excessive Smartphone Use: A Systematic Review and Meta-Analysis

Research RF Safe Research Library Dec 5, 2022

This systematic review and meta-analysis synthesized observational MRI studies comparing excessive smartphone users with regular users. It reports smaller brain volumes in excessive smartphone users, especially in subcortical regions, and notes that the association was more pronounced in adolescents than adults. It…

Wideband Self-Grounded Bow-Tie Antenna for Thermal MR.

Research RF Safe Research Library Jan 1, 2020

This engineering study designed and tested a compact wideband self-grounded bow-tie RF antenna module for a whole-body 7.0 T MRI system, aiming to enable 1H/19F MRI, MR thermometry, and broadband RF thermal intervention. The authors report validated B1 efficiency measurements and phantom-based heating experiments…

Structural and functional correlates of smartphone addiction

Research RF Safe Research Library Jan 1, 2020

This cross-sectional MRI study compared individuals meeting psychometric criteria for smartphone addiction (n=22) with controls (n=26). It reports lower gray matter volume in several regions (including left anterior insula and parahippocampal cortex) and lower intrinsic activity in the right anterior cingulate cortex…

Non-Ionizing Radiation in Swedish Health Care-Exposure and Safety Aspects.

Research RF Safe Research Library Jan 1, 2019

This review describes non-ionizing radiation (EMF and optical radiation) methods used in Swedish health care and considers anticipated exposure levels and potential hazards. The authors report that acute effects cannot be ruled out for MRI, transcranial magnetic stimulation, and electrosurgery, and that optical…

Evaluation of MRI RF electromagnetic field induced heating near leads of cochlear implants.

Research RF Safe Research Library Jan 1, 2018

This simulation study evaluated RF-induced heating near cochlear implant leads during 1.5 T MRI using a transfer function method. Across studied configurations, the average temperature rise was 0.79 °C and the maximum was 2.80 °C at a whole-body average SAR of 2 W/kg. The authors report that lead trajectory and MRI…

Effects of short and long term electromagnetic fields exposure on the human hippocampus.

Research RF Safe Research Library Jan 1, 2017

This study compared 60 healthy female medical students grouped by self-reported daily mobile phone use by the head (90 min). MRI/MRS analyses found no significant differences in hippocampal volume or in choline, creatine, and N-acetyl aspartate between groups. However, the higher-use group showed poorer performance…

Radio frequency induced heating of an insulated wire during magnetic resonance imaging.

Research RF Safe Research Library Jan 1, 2016

This engineering study investigated RF-induced power deposition near straight insulated leads in an MRI context under different incident electric field profiles. Using 3-D electromagnetic simulations, the authors compared simulation-derived power deposition with implant model predictions. For the setups examined,…

A wearable bluetooth LE sensor for patient monitoring during MRI scans.

Research RF Safe Research Library Jan 1, 2016

This engineering paper reports a prototype wearable patient-monitoring device that transmits vital-sign measurements via Bluetooth LE during MRI. Across 7 MRI acquisitions (25 minutes total), the authors report no Bluetooth packet loss, increased PPG noise during MRI, and no effect on temperature/humidity readings.…

Effects of Anatomical Differences on Electromagnetic Fields, SAR, and Temperature Change.

Research RF Safe Research Library Jan 1, 2016

This engineering study evaluates how anatomical/geometric differences affect MRI RF safety metrics. Simulations and a bovine-phantom experiment found that similar transmit B-field patterns can coincide with notably different peak SAR and temperature rise. The authors highlight challenges in using…

Visualization of the radiofrequency lesion after pulmonary vein isolation using delayed enhancement magnetic resonance imaging fused with magnetic resonance angiography.

Research RF Safe Research Library Jan 1, 2015

This study evaluated whether fusing delayed enhancement MRI (DE-MRI) with magnetic resonance angiography (MRA) improves visualization of radiofrequency ablation lesions after pulmonary vein isolation. Eighteen atrial fibrillation ablation patients underwent both imaging approaches, and two observers scored lesion…

Visualizing radiofrequency lesions using delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation: A modification of the method used by the University of Utah group.

Research RF Safe Research Library Jan 1, 2015

This feasibility study evaluated whether delayed-enhancement MRI (DE-MRI) using commercially available tools could visualize radiofrequency ablation lesions in Japanese patients with atrial fibrillation. Of 15 scans, 3 were uninterpretable due to low image quality, and lesions were visualized in 8 of the remaining 12…

Comparison of submucosal resection and radiofrequency turbinate volume reduction for inferior turbinate hypertrophy: evaluation by magnetic resonance imaging.

Research RF Safe Research Library Jan 1, 2014

This prospective randomized study compared submucosal resection (SMR) with radiofrequency turbinate volume reduction (RFTVR) in 60 patients with inferior turbinate hypertrophy. Both procedures significantly reduced turbinate volume and improved nasal obstruction symptoms and nasal inspiratory peak flow by 2 months.…

Ultrafast volumetric B1 (+) mapping for improved radiofrequency shimming in 3 tesla body MRI.

Research RF Safe Research Library Jan 1, 2014

This engineering/clinical MRI methods study evaluated ultrafast volumetric DREAM B1+ mapping to refine patient-adaptive RF shimming at 3T. In 20 patients and three volunteers, a multi-slice adaptive RF shimming approach reduced flip-angle deviations and improved B1+ homogeneity compared with central-slice-based…

Liver lesion conspicuity during real-time MR-guided radiofrequency applicator placement using spoiled gradient echo and balanced steady-state free precession imaging.

Research RF Safe Research Library Jan 1, 2014

This retrospective study evaluated liver lesion conspicuity during real-time MR-guided radiofrequency applicator placement using spoiled GRE and balanced SSFP MRI sequences in a 1.5 T scanner. Lesion detectability categories and contrast-to-noise ratio (CNR) were compared for hepatocellular carcinoma and liver…

The effect of extremely low frequency pulsed electromagnetic field on in vitro fertilization success rate in N MRI mice.

Research RF Safe Research Library Jan 1, 2014

This randomized comparative animal study tested whether extremely low frequency pulsed electromagnetic field exposure affects IVF success in NMRI mice. Mice in the experimental group were exposed to a 1.3 mT pulsed field at 4 kHz for 5 hours during the IVF process. Although the exposed group showed a higher IVF…

The alteration of spontaneous low frequency oscillations caused by acute electromagnetic fields exposure.

Research RF Safe Research Library Jan 1, 2014

This double-blind, randomized, crossover study examined whether 30 minutes of near-field LTE radiofrequency exposure near the right ear alters resting-state brain activity measured by fMRI. The authors report decreased ALFF in multiple temporal and frontal/paracentral regions after real exposure compared with sham,…

A radiofrequency coil to facilitate B₁⁺ shimming and parallel imaging acceleration in three dimensions at 7 T.

Research RF Safe Research Library Jan 1, 2011

This paper reports the development of a 15-channel transmit-receive RF coil for 7 T human brain MRI, using a hybrid decoupling approach to support element placement along three axes. The design is presented as enabling B1+ shimming and parallel imaging acceleration in three dimensions, with reported isolation and…

Measurement of creatine kinase reaction rate in human brain using magnetization transfer image-selected in vivo spectroscopy (MT-ISIS) and a volume ³¹P/¹H radiofrequency coil in a clinical 3-T MRI system.

Research RF Safe Research Library Jan 1, 2011

This paper describes a new magnetization transfer 31P MRS approach (MT-ISIS) for measuring the creatine kinase forward reaction rate in the human brain using a volume 31P/1H RF coil on a clinical 3-T MRI system. The method aims to reduce acquisition time (30 min), avoid scalp muscle contamination, improve RF…

Increased blood oxygen level-dependent (BOLD) sensitivity in the mouse somatosensory cortex during electrical forepaw stimulation using a cryogenic radiofrequency probe.

Research RF Safe Research Library Jan 1, 2011

This engineering-focused mouse fMRI study evaluated a 400-MHz cryogenic RF probe (CryoProbe) versus a conventional room-temperature surface coil during electrical forepaw stimulation. The CryoProbe increased image SNR and temporal SNR and reduced temporal noise compared with the room-temperature coil. The authors…

Reduction of implant RF heating through modification of transmit coil electric field.

Research RF Safe Research Library Jan 1, 2011

This engineering study describes modifying MRI RF transmit coil electric-field distributions to create electric field-free zones without substantially changing transmit sensitivity. Phantom experiments are reported to show reduced implant heating when a zero electric-field plane is aligned with the implant location.…

Correction of main and transmit magnetic field (B0 and B1) inhomogeneity effects in multicomponent-driven equilibrium single-pulse observation of T1 and T2.

Research RF Safe Research Library Jan 1, 2011

This methods paper addresses how B0 (main field) and B1 (transmit field) inhomogeneities can bias SPGR and bSSFP steady-state MRI signals used for multicomponent T1/T2 relaxometry and myelin water analysis. It describes using DESPOT1-HIFI to calibrate flip angles and adding a B0-related parameter with multiple…

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