A5011157612- Advanced MRI Techniques and Applications
- Microwave Imaging and Scattering Analysis
- Wireless Body Area Networks
- Advanced NMR Techniques and Applications
- Antenna Design and Analysis
- Ultrasound Imaging and Elastography
- Molecular Biology Techniques and Applications
- Electron Spin Resonance Studies
- Lanthanide and Transition Metal Complexes
- Prostate Cancer Treatment and Research
- Cancer-related molecular mechanisms research
- Radio Frequency Integrated Circuit Design
- Advanced Neuroimaging Techniques and Applications
- Medical Imaging Techniques and Applications
- Hybrid Renewable Energy Systems
- Energy Harvesting in Wireless Networks
- Neurological disorders and treatments
- Ultrasound and Hyperthermia Applications
- Atomic and Subatomic Physics Research
Hankuk University of Foreign Studies
2024-2025
University of Ulsan
2022-2023
University of Minnesota
2017-2023
Resonance Research (United States)
2017-2023
Seoul National University
2021
Multi-element transmit arrays with low peak 10 g specific absorption rate (SAR) and high SAR efficiency (defined as ( [Formula: see text]SAR text] are essential for ultra-high field (UHF) magnetic resonance imaging (MRI) applications. Recently, the adaptation of dipole antennas used MRI coil elements in multi-channel has provided community a technological solution capable producing uniform images at these strengths. However, human head-sized consisting have practical limitation to number...
We evaluated a 16-channel loop + dipole (LD) transceiver antenna array with improved specific absorption rate (SAR) efficiency for 10.5 Tesla (T) human head imaging applications. Three different designs equal inner dimensions were considered: an 8-channel antenna, loop, and LD arrays. Signal-to-noise ratio (SNR) B <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> <sup xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> (in units of μT per...
Changes in specific circulating RNA (circRNA) expressions can serve as diagnostic noninvasive biomarkers for prostate cancer (PCa). However, there are still unmet needs, such unclear types and roles of circRNAs, PCa detection benign prostatic hyperplasia (BPH) by unstandardized methods, limitations sample volume capacity low circRNA concentrations. This study reports a simple rapid enrichment isolation technique named "HAZIS-CirR" the analysis urinary circRNAs. The method utilizes...
For human brain magnetic resonance imaging (MRI), high channel count ( ≥ 32 ) radiofrequency receiver coil arrays are utilized to achieve maximum signal-to-noise ratio (SNR) and accelerate parallel techniques. With ultra-high field (UHF) MRI at 7 tesla (T) higher, dipole antenna have been shown generate SNR in the deep regions of brain, however array elements exhibit increased electromagnetic coupling with one another, making construction more difficult increasing number elements. Compared a...
For ultra-high field and frequency (UHF) magnetic resonance imaging (MRI), the associated short wavelengths in biological tissues leads to penetration homogeneity issues at 10.5 tesla (T) require antenna transmit arrays for efficiently generated 447 MHz B1+ fields (defined as radiofrequency (RF) by RF coils). Previously, we evaluated a 16-channel combined loop + dipole (LD) T head array. While LD array configuration did not achieve desired efficiency, it showed an improvement of specific...
In this letter, we evaluate antenna designs for ultra-high frequency and field (UHF) human brain magnetic resonance imaging (MRI) at 10.5 tesla (T). Although MRI such UHF is expected to provide major signal-to-noise gains, the of interest, 447 MHz, presents us with challenges regarding improved B1+ efficiency, image homogeneity, specific absorption rate (SAR), element decoupling array configurations. To address these challenges, propose use both monopole dipole antennas in a novel hybrid...
A loop+dipole transceiver antenna array was designed for 447 MHz /10.5 tesla human head imaging. This achieved by a geometrically decoupled combination of loop and dipole without inter-element decoupling circuitry. We made comparisons between an 8-channel only array, 16-channel combined through simulation using the finite difference time domain (FDTD) method MR imaging experiments.
For human head magnetic resonance imaging at 10.5 tesla (T), we built an 8-channel transceiver dipole antenna array and evaluated the influence of coaxial feed cables. The cables was in simulation compared against a physically constructed terms transmit field (B1+) specific absorption rate (SAR) efficiency. A substantial drop (23.1% 20.7% experiment) B1+ efficiency observed with tight cable setup. investigation location, center-fed to two end-fed arrays: monopole sleeve arrays. results...
A 16-channel transmit array intended for interchangeable use with up to 128 receiver arrays is being developed 10.5T/ 447MHz head imaging. In initial work, presented here we evaluated a dual row loop design and compare predicted achievable performance of this transmitter without 32 channel receive only insert. Both excellent intra element decoupling high isolation between the insert was achieved.
In vivo 31 P magnetic resonance spectroscopy (MRS) provides a unique tool for the non‐invasive study of brain energy metabolism and mitochondrial function. The assessment bioenergetic impairment in different regions is essential to understand pathophysiology progression human diseases. This article presents simple effective approach which allows interleaved measurement spectra imaging from two distinct interest with dynamic B 0 shimming capability. A transistor–transistor logic controller...
We evaluated in simulation and experimentally the effects that insertion of a 32-channel sleeve antenna receiver array has on B1+ SAR performance 447 MHz/10.5 T 16-channel loop transmitter array. For this we carefully developed accurate models both receiver, compared simulated with experimental expected efficiency without insert.
Motivation: To explore the SNR performance of Loop and Sleeve antennas for multi-channel human head imaging at 10.5T. Goal(s): Validation achievable receive loop sleeve with same number channels. Approach: Simulation based analysis between Results: We obtained compared simulated data antennas. For channels (1, 3, 5, 32-channels), each map was similar coverage. Our experimental indicates an enhancement achieved 32-channel antenna array to array. Impact: simulations indicate that a...
For whole brain human head imaging at 10.5 Tesla, we interlaced a 16-channel sleeve antenna transceiver with asymmetric dipole receiver for combined, close fitting transmit/32 -channel array. Integration of high dielectric constant material (HDC) significantly improved performance in the upper brain. Simulation results indicate excellent B1 efficiency and coverage combined array 447 MHz. To further improve performance, developed new on-coil transmit/receive (T/R) switches capable...
Recently, the susceptibility source separation method, &chi;-separation, was suggested to separate paramagnetic and diamagnetic distributions in brain, potentially providing quantitative information of iron myelin. However, ill-posed nature dipole-inversion has hindered accurate estimation direct comparison with histology. Here, we extended model for multi-orientation GRE, resolving ill-posedness. The new is applied in-vivo ex-vivo, revealing exquisite details distribution. When results...