Toward cardiac electrophysiological mapping based on micro-Tesla NMR: a novel modality for localizing the cardiac reentry

Kim, Ki Woong

doi:10.1063/1.4731801

Cited by 5 publications

(4 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Gd chelates were dissolved into deionized water to four different concentrations, and the relaxation times T [11] to achieve the corresponding thermal equilibrium value. If the data points of a few evolution steps are recorded and fitted by the single exponential decay function, T B 0 1 can be derived as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Field Dependence Study of Commercial Gd Chelates With SQUID Detection

Huang

Tao

Chang

et al. 2016

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

The contrast agents (CAs), which can enhance the image contrast by changing the relaxation times in the target locations, are widely used in clinical high-field magnetic resonance imaging (MRI). However, the commercial clinical CAs have attracted little attention in ultralow field (ULF) MRI, whose measurement field is four orders of magnitude lower than that of the clinical high-field counterpart. In this paper, we measure the relaxivity levels of three gadolinium (Gd)-based commercial CAs (Gd-DTPA, Gd-EOB-DTPA, and Gd-DTPA-BMA) with our four-channel magnetically unshielded ULF-MRI system using low-T c superconducting quantum interference devices as detectors. The system has a 0.65-T permanent-magnet pair as prepolarization field B p and applies a static B 0 field of 129 uT. We compare the longitudinal relaxivity levels of the CAs at B p and B 0 field strengths, as well as the reported values at 1.5 T. The results show that the relaxivity levels of three commercial CAs at 129 uT are all about twice those at high fields, which demonstrates one particular advantage of ULF-MRI.Index Terms-Gadolinium (Gd), magnetic resonance imaging (MRI) contrast agent (CA), relaxivity, superconducting quantum interference devices (SQUIDs), ultralow field (ULF) MRI.

show abstract

Section: Resultsmentioning

confidence: 99%

“…The sensitivity loss of Faraday coil detection at [11]. The relaxation characteristics of Gd-based CAs are seldom studied at ULF.…”

Section: Introductionmentioning

confidence: 99%

Field Dependence Study of Commercial Gd Chelates With SQUID Detection

Huang

Tao

Chang

et al. 2016

IEEE Trans. Appl. Supercond.

View full text Add to dashboard Cite

show abstract

“…A number of ULF-MRI-specific imaging techniques have emerged, including rotary-scanning acquisition (RSA) [3], temperature mapping [4], signalenhancing dynamic nuclear polarization [5,6], imaging of electric current density (CDI) [7][8][9], and making use of significant differences in NMR relaxation mechanisms at ULF compared to tesla-range fields [10][11][12]. Several groups have also investigated possibilities to directly detect changes in the NMR signal due to neural currents in the brain [13][14][15][16] and electrical activation of the heart [17]. A further notable field of research now focuses on combining ULF MRI with magnetoencephalography (MEG).…”

Section: Introductionmentioning

confidence: 99%

Superconducting receiver arrays for magnetic resonance imaging

Zevenhoven

Mäkinen²,

Ilmoniemi³

2020

Biomed. Phys. Eng. Express

View full text Add to dashboard Cite

Superconducting QUantum-Interference Devices (SQUIDs) make magnetic resonance imaging (MRI) possible in ultra-low microtesla-range magnetic fields. In this work, we investigate the design parameters affecting the signal and noise performance of SQUID-based sensors and multichannel magnetometers for MRI of the brain. Besides sensor intrinsics, various noise sources along with the size, geometry and number of superconducting detector coils are important factors affecting the image quality. We derive figures of merit based on optimal combination of multichannel data and provide tools for understanding the signal detection and the different noise mechanisms, as well as a guide to making design decisions for both MRI-and sensor-oriented readers.

show abstract

“…SQUID-based microtesla NMR has paved the way for new biomedical measurements under low magnetic field conditions, for example, chemical analysis from a J -coupling spectrum [ 20 ], simultaneous proton density imaging with magnetoencephalography [ 21 , 22 ], direct neutral current imaging [ 23 – 25 ], brainwave magnetic resonance [ 18 ], and heart magnetic resonance [ 26 ]. All of these measurements are difficult to achieve with conventional high-field NMR/MRIs.…”

Section: Introductionmentioning

confidence: 99%

T1Relaxation Measurement ofEx-VivoBreast Cancer Tissues at Ultralow Magnetic Fields

Lee

Shim

Kim

et al. 2015

BioMed Research International

Self Cite

View full text Add to dashboard Cite

We investigated T 1 relaxations of ex-vivo cancer tissues at low magnetic fields in order to check the possibility of achieving a T 1 contrast higher than those obtained at high fields. The T 1 relaxations of fifteen pairs (normal and cancerous) of breast tissue samples were measured at three magnetic fields, 37, 62, and 122 μT, using our superconducting quantum interference device-based ultralow field nuclear magnetic resonance setup, optimally developed for ex-vivo tissue studies. A signal reconstruction based on Bayesian statistics for noise reduction was exploited to overcome the low signal-to-noise ratio. The ductal and lobular-type tissues did not exhibit meaningful T 1 contrast values between normal and cancerous tissues at the three different fields. On the other hand, an enhanced T 1 contrast was obtained for the mucinous cancer tissue.

show abstract

Toward cardiac electrophysiological mapping based on micro-Tesla NMR: a novel modality for localizing the cardiac reentry

Cited by 5 publications

References 21 publications

Field Dependence Study of Commercial Gd Chelates With SQUID Detection

Field Dependence Study of Commercial Gd Chelates With SQUID Detection

Superconducting receiver arrays for magnetic resonance imaging

T1Relaxation Measurement ofEx-VivoBreast Cancer Tissues at Ultralow Magnetic Fields

Contact Info

Product

Resources

About