Analytically-based approach for the analysis of MRI volume coil loaded with multilayered cylinder

2012 ◽  
Author(s):  
G. Tiberi ◽  
M. Tosetti ◽  
J. Tropp ◽  
A. Monorchio
Keyword(s):  
Volume Coil ◽  
Multilayered Cylinder

scholarly journals Implantable NMR Microcoils in Rats: A New Tool for Exploring Tumor Metabolism at Sub-Microliter Scale?

Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 176
Author(s):  
Justine Deborne ◽  
Noël Pinaud ◽  
Yannick Crémillieux
Keyword(s):  
Magnetic Resonance ◽  
Tumor Model ◽  
Surface Coil ◽  
Regions Of Interest ◽  
7 Tesla ◽  
Resonance Spectroscopy ◽  
Volume Coil ◽  
Detection Volume ◽  
The Right

The aim of this study was to evaluate the potential of a miniaturized implantable nuclear magnetic resonance (NMR) coil to acquire in vivo proton NMR spectra in sub-microliter regions of interest and to obtain metabolic information using magnetic resonance spectroscopy (MRS) in these small volumes. For this purpose, the NMR microcoils were implanted in the right cortex of healthy rats and in C6 glioma-bearing rats. The dimensions of the microcoil were 450 micrometers wide and 3 mm long. The MRS acquisitions were performed at 7 Tesla using volume coil for RF excitation and microcoil for signal reception. The detection volume of the microcoil was measured equal to 450 nL. A gain in sensitivity equal to 76 was found in favor of implanted microcoil as compared to external surface coil. Nine resonances from metabolites were assigned in the spectra acquired in healthy rats (n = 5) and in glioma-bearing rat (n = 1). The differences in relative amplitude of choline, lactate and creatine resonances observed in glioma-bearing animal were in agreement with published findings on this tumor model. In conclusion, the designed implantable microcoil is suitable for in vivo MRS and can be used for probing the metabolism in localized and very small regions of interest in a tumor.

Numerical investigation of the interaction of a plane wave with a multilayered cylinder in the ground

1992 ◽  
Vol 33 (5) ◽  
pp. 758-767
Author(s):  
K. Atabaev ◽  
N. Mamadaliev ◽  
R. K. Khanov ◽  
Sh. D. Shamgunov
Keyword(s):  
Plane Wave ◽  
Numerical Investigation ◽  
Multilayered Cylinder

High field volume coil with unbalance current distribution for MRI applications of rodents

2010 ◽  
Author(s):  
O. R. Marrufo ◽  
J. Hernández ◽  
A. O. Rodríguez ◽  
Maria-Ester Brandan ◽  
Flora Herrera-Martinez ◽  
...  
Keyword(s):  
Current Distribution ◽  
High Field ◽  
Volume Coil

Volume and surface coil simultaneous reception (VSSR) method for intensity inhomogeneity correction in MRI

2021 ◽  
pp. 1-12
Author(s):  
Lin Wu ◽  
Tian He ◽  
Jie Yu ◽  
Hang Liu ◽  
Shuang Zhang ◽  
...  
Keyword(s):  
Bias Field ◽  
Correction Method ◽  
Surface Coil ◽  
Intensity Inhomogeneity ◽  
Acquisition Time ◽  
Surface Coils ◽  
In Vivo Experiments ◽  
Inhomogeneity Correction ◽  
Volume Coil

BACKGROUND: Addressing intensity inhomogeneity is critical in magnetic resonance imaging (MRI) because associated errors can adversely affect post-processing and quantitative analysis of images (i.e., segmentation, registration, etc.), as well as the accuracy of clinical diagnosis. Although several prior methods have been proposed to eliminate or correct intensity inhomogeneity, some significant disadvantages have remained, including alteration of tissue contrast, poor reliability and robustness of algorithms, and prolonged acquisition time. OBJECTIVE: In this study, we propose an intensity inhomogeneity correction method based on volume and surface coils simultaneous reception (VSSR). METHODS: The VSSR method comprises of two major steps: 1) simultaneous image acquisition from both volume and surface coils and 2) denoising of volume coil images and polynomial surface fitting of bias field. Extensive in vivo experiments were performed considering various anatomical structures, acquisition sequences, imaging resolutions, and orientations. In terms of correction performance, the proposed VSSR method was comparatively evaluated against several popular methods, including multiplicative intrinsic component optimization and improved nonparametric nonuniform intensity normalization bias correction methods. RESULTS: Experimental results show that VSSR is more robust and reliable and does not require prolonged acquisition time with the volume coil. CONCLUSION: The VSSR may be considered suitable for general implementation.

An artificial magnetic shield for a volume coil for 7T MRI

2019 ◽  
Author(s):  
Anna Hurshkainen ◽  
Ksenia Lezhennikova ◽  
Constantin Simovski ◽  
Stanislav Glybovski
Keyword(s):  
Magnetic Shield ◽  
Volume Coil
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