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Purpose: The purpose of this study is to demonstrate a method for Specific Absorption Rate (SAR) reduction for T2-FLAIR MRI sequences at 7T by predicting the required adiabatic pulse power and scaling the amplitude in a slice-wise fashion.…

Image and Video Processing · Electrical Eng. & Systems 2020-11-25 Shahrokh Abbasi-Rad , Kieran O'Brien , Samuel Kelly , Viktor Vegh , Anders Rodell , Yasvir Tesiram , Jin Jin , Markus Barth , Steffen Bollmann

A magnitude-least-squares radiofrequency pulse design algorithm is reported which uses interleaved exact and stochastically-generated inexact updates to escape local minima and find low-cost solutions. Inexact updates are performed using a…

Medical Physics · Physics 2024-07-23 Jonathan B. Martin , Charlotte R. Sappo , Benjamin M. Hardy , William A. Grissom

Existing optimal control protocols for mitigating the effects of relaxation and/or RF inhomogeneity on broadband pulse performance are extended to the more difficult problem of designing robust, refocused, frequency selective excitation…

Instrumentation and Detectors · Physics 2015-06-03 Thomas E. Skinner , Naum I. Gershenzon , Manoj Nimbalkar , Steffen J. Glaser

Adiabatic braiding of Majorana zero modes can be used for topologically protected quantum information processing. While extremely robust to many environmental perturbations, these systems are vulnerable to noise with high-frequency…

Quantum Physics · Physics 2018-07-02 Kyle Ritland , Armin Rahmani

Purpose: Rapid 2D RF pulse design with subject specific $B_1^+$ inhomogeneity and $B_0$ off-resonance compensation at 7 T predicted from convolutional neural networks is presented. Methods: The convolution neural network was trained on half…

Cardiac T1 mapping provides critical quantitative insights into myocardial tissue composition, enabling the assessment of pathologies such as fibrosis, inflammation, and edema. However, the inherently dynamic nature of the heart imposes…

Image and Video Processing · Electrical Eng. & Systems 2025-12-09 Tamir Shor , Moti Freiman , Chaim Baskin , Alex Bronstein

Cardiac T1 mapping is a valuable quantitative MRI technique for diagnosing diffuse myocardial diseases. Traditional methods, relying on breath-hold sequences and cardiac triggering based on an ECG signal, face challenges with patient…

Image and Video Processing · Electrical Eng. & Systems 2025-03-10 Eyal Hanania , Adi Zehavi-Lenz , Ilya Volovik , Daphna Link-Sourani , Israel Cohen , Moti Freiman

Purpose: To address the systematic bias in whole-brain dual flip angle (DFA) T1-mapping at 7T by optimizing the flip angle pair and carefully selecting RF pulse shape and duration. Theory and Methods: Spoiled gradient echoes can be used to…

Medical Physics · Physics 2020-01-28 H. Olsson , M. Andersen , R. Wirestam , J. Lätt , G. Helms

Calibration is nowadays one of the most important processes involved in the extraction of valuable data from measurements. The current availability of an optimum data cube measured from a heterogeneous set of instruments and surveys relies…

Instrumentation and Methods for Astrophysics · Physics 2012-08-13 Maria Jose Marquez

We present robust radio frequency (rf) pulses that tolerate a factor of six inhomogeneity in the B1 field, significantly enhancing the potential of toroid cavity resonators for NMR spectroscopic applications. Both point-to-point (PP) and…

Chemical Physics · Physics 2015-05-20 Thomas E. Skinner , Michael Braun , Klaus Woelk , Naum I. Gershenzon , Steffen J. Glaser

We address the experimentally relevant problem of robust mitigation of dephasing noise acting on a qubit. We first present an extension of a method for representing $1/\omega^{\alpha}$ noise developed by Kuopanportti et al. to the efficient…

Quantum Physics · Physics 2010-06-01 Kevin C. Young , Dylan J Gorman , K. Birgitta Whaley

Purpose: Neurovascular MRI suffers from a rapid drop in B1+ into the neck when using transmit head coils at 7T. One solution to improving B1+ magnitude in the major feeding arteries in the neck is to use custom RF shims on parallel transmit…

Medical Physics · Physics 2023-01-02 Matthijs H. S. de Buck , Peter Jezzard , Aaron T. Hess

Ultrahigh field (UHF) Magnetic Resonance Imaging (MRI) provides a higher signal-to-noise ratio and, thereby, higher spatial resolution. However, UHF MRI introduces challenges such as transmit radiofrequency (RF) field (B1+) inhomogeneities,…

Computer Vision and Pattern Recognition · Computer Science 2025-02-07 Zhengyi Lu , Hao Liang , Xiao Wang , Xinqiang Yan , Yuankai Huo

Reconfigurable intelligent surface (RIS) architectures not limited to diagonal phase shift matrices have recently been considered to increase their flexibility in shaping the wireless channel. One of these beyond-diagonal RIS or BD-RIS…

Information Theory · Computer Science 2023-07-21 Ignacio Santamaria , Mohammad Soleymani , Eduard Jorswieck , Jesus Gutierrez

This study presents a noise-robust framework for 1-bit diffraction tomography, a novel imaging approach that relies on intensity-only binary measurements obtained through coded apertures. The proposed reconstruction scheme leverages random…

Information Theory · Computer Science 2025-05-27 Pengwen Chen , Albert Fannjiang

Body-conduction microphone signals (BMS) bypass airborne sound, providing strong noise resistance. However, a complementary modality is required to compensate for the inherent loss of high-frequency information. In this study, we propose a…

Sound · Computer Science 2025-08-29 Yunsik Kim , Yoonyoung Chung

Broadband frequency-selective fading channels usually have the inherent sparse nature. By exploiting the sparsity, adaptive sparse channel estimation (ASCE) algorithms, e.g., least mean square with reweighted L1-norm constraint (LMS-RL1)…

Information Theory · Computer Science 2015-04-29 Guan Gui , Li Xu

The amplification obtained using weak values is quantified through a detailed investigation of the signal to noise ratio for an optical beam deflection measurement. We show that for a given deflection, input power and beam radius, the use…

Quantum Physics · Physics 2009-10-14 David J. Starling , P. Ben Dixon , Andrew N. Jordan , John C. Howell

Purpose: Phosphorus saturation-transfer experiments can quantify metabolic fluxes non-invasively. Typically, the forward flux through the creatine-kinase reaction is investigated by observing the decrease in phosphocreatine (PCr) after…

In Brain-Computer Interface (BCI) applications, noise presents a persistent challenge, often compromising the quality of EEG signals essential for accurate data interpretation. This paper focuses on optimizing the signal-to-noise ratio…

Neurons and Cognition · Quantitative Biology 2025-07-24 Eva Guttmann-Flury , Yanyan Wei , Shan Zhao
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