Results 1 to 10 of about 5,585,535 (119)

Joint Inversion of Receiver Functions and Apparent Incidence Angles to Determine the Crustal Structure of Mars

Geophysical Research Letters, 2023
Recent estimates of the crustal thickness of Mars show a bimodal result of either ∼20 or ∼40 km beneath the InSight lander. We propose an approach based on random matrix theory applied to receiver functions (RFs) to further constrain the subsurface ...
Rakshit Joshi, Brigitte Knapmeyer‐Endrun, Klaus Mosegaard, M. A. Wieczorek, Heiner Igel, Ulrich R. Christensen, Philippe Lognonné   +6 more
doaj   +2 more sources

Enhanced 2D Spiral Cine DENSE MRI Using Low-Rank Denoising for Improved Apparent Signal-to-Noise Ratio, Spatial Resolution, Efficiency, Accuracy, and Accessibility. [PDF]

Magn Reson Med
ABSTRACT Purpose To develop a denoising technique for displacement encoding with stimulated echoes (DENSE) MRI that improves spatial resolution, efficiency, and accuracy, and enhances accessibility by implementing DENSE MRI at 0.55 T. Methods We developed a low‐rank denoising technique, which leverages multidimensional spiral cine DENSE MRI data for ...
Shih SF, Wu Y, Li S, Ming Z, Pogosyan A, Han F, Wu HH, Finn JP, Nguyen KL, Zhong X.   +9 more
europepmc   +2 more sources

Detail-preserving denoising of CT and MRI images via adaptive clustering and non-local means algorithm [PDF]

Scientific Reports
Medical imaging systems such as computed tomography (CT) and magnetic resonance imaging (MRI) are vital tools in clinical diagnosis and treatment planning.
Mohit Sharma, Ayush Dogra, Bhawna Goyal, Anita Gupta, Manob Jyoti Saikia   +4 more
doaj   +2 more sources

Eigenvalue Based Detection by Combining Eigenvector-Correlated Signal in Low SNR Environment

IET Signal Processing
Eigenvalue detection is extensively utilized in numerous applications, including spectrum sensing in cognitive radio. However, the characteristics of the Tracy–Widom (TW2) distribution and its lack of accurate close-form expression limit the detection ...
Wei Ge, Chao Yang, Yizhou Feng, Xiaofang Deng, Lin Zheng   +4 more
doaj   +2 more sources

Sampling of non-Gaussian Ensemble Average Propagators for the simulation of diffusion magnetic resonance images. [PDF]

Magn Reson Med
Abstract Purpose (a) To design a methodology for drawing random samples of any Ensemble Average Propagator (EAP) (b) to modify the KomaMRI simulator to accommodate them as realistic spin movements to simulate diffusion MRI (dMRI) and (c) to compare these simulations with those based on the Diffusion Tensor (DT) model.
Rodríguez-Galván JR, Villacorta-Aylagas P, Merino-Caviedes S, Simmross-Wattenberg F, Castillo-Passi C, Irarrazaval P, Tristán-Vega A, Alberola-López C.   +7 more
europepmc   +2 more sources

Local Laws for Sparse Sample Covariance Matrices

Mathematics, 2022
We proved the local Marchenko–Pastur law for sparse sample covariance matrices that corresponded to rectangular observation matrices of order n×m with n/m→y (where y>0) and sparse probability npn>logβn (where β>0).
Alexander N. Tikhomirov, Dmitry A. Timushev   +1 more
doaj   +2 more sources

Reducing thermal noise in high-resolution quantitative magnetic resonance imaging rotating frame relaxation mapping of the human brain at 3 T. [PDF]

NMR Biomed
Whole‐brain rotating frame relaxation (RFR) mapping is generally implemented at moderate spatial resolutions. Our results showed that applying transform domain NORDIC (T‐NORDIC) before fitting improves the reliability of RFR parameter estimations, especially at higher spatial resolution, a benefit that can be critical for clinical applications ...
Ponticorvo S, Canna A, Moeller S, Akcakaya M, Metzger GJ, Filip P, Eberly LE, Michaeli S, Mangia S.   +8 more
europepmc   +2 more sources

Feasibility of strong diffusion encoding and fast readout using a plug-and-play head gradient insert at 7 T. [PDF]

Magn Reson Med
Purpose Diffusion weighting is achieved by the application of external field gradients typically for tens of milliseconds, during which the signal also substantially decays due to inherent T2 relaxation. Employing strong gradients will shorten the echo time (TE) and increase the signal‐to‐noise ratio.
Arends GC, Versteeg E, De Luca A, Marc F, Roos THM, Klomp DWJ, Froeling M, Siero JCW, Tax CMW.   +8 more
europepmc   +2 more sources

Compressed sensing reconstruction for high-SNR, rapid dissolved ¹²⁹Xe gas exchange MRI. [PDF]

Magn Reson Med
Abstract Purpose Three‐dimensional hyperpolarized 129Xe gas exchange imaging suffers from low SNR and long breath‐holds, which could be improved using compressed sensing (CS). The purpose of this work was to assess whether gas exchange ratio maps are quantitatively preserved in CS‐accelerated dissolved‐phase 129Xe imaging and to investigate the ...
Pilgrim-Morris JH, Collier GJ, Munro RS, Norquay G, Stewart NJ, Wild JM.   +5 more
europepmc   +2 more sources

Pore size estimation in axon-mimicking microfibers with diffusion-relaxation MRI. [PDF]

Magn Reson Med
Abstract Purpose This study aims to evaluate two distinct approaches for fiber radius estimation using diffusion‐relaxation MRI data acquired in biomimetic microfiber phantoms that mimic hollow axons. The methods considered are the spherical mean power‐law approach and a T2‐based pore size estimation technique.
Canales-Rodríguez EJ, Pizzolato M, Zhou FL, Barakovic M, Thiran JP, Jones DK, Parker GJM, Dyrby TB.   +7 more
europepmc   +2 more sources