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Updated: Jun 2, 2026

Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform

Time Multiplexing Super Resolving Technique for Imaging from a Moving Platform

Published on: February 12, 2014

Time efficient design of multi dimensional RF pulses: application of a multi shift CGLS algorithm.

Alessandro Sbrizzi¹, Hans Hoogduin, Jan J Lagendijk

¹Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands. a.sbrizzi@umcutrecht.nl

Magnetic Resonance in Medicine

|May 7, 2011

Summary

This study introduces a faster method for designing radio frequency pulses using a conjugate gradients algorithm. It significantly reduces computation time by eliminating the need to test multiple regularization parameters.

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Last Updated: Jun 2, 2026

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Generation and Coherent Control of Pulsed Quantum Frequency Combs

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Published on: June 8, 2018

Area of Science:

Magnetic Resonance Imaging
Pulse Sequence Design
Numerical Methods

Background:

Designing radio frequency (RF) excitation pulses for magnetic resonance imaging (MRI) often involves solving complex least squares problems.
Numerical solutions typically require regularization with a penalty parameter (λ), but the optimal value is often unknown beforehand.
This necessitates solving the problem multiple times with varying λ, increasing computational cost.

Purpose of the Study:

To develop a time-efficient algorithm for designing multi-dimensional RF excitation pulses.
To eliminate the need for a priori knowledge of the optimal regularization parameter in RF pulse design.
To reduce the computational burden associated with RF pulse design in the small flip angle regime.

Main Methods:

Application of a conjugate gradients-based algorithm for RF pulse design.
Implementation of a method that does not require prior knowledge of the optimal regularization parameter.
Comparison of the new algorithm's performance against standard conjugate gradients for least squares.

Main Results:

The conjugate gradients-based algorithm designs RF pulses efficiently without needing to know the optimal regularization parameter.
Achieved a significant reduction in computation time, approximately a factor of 10 compared to standard methods.
Simulations demonstrate the effectiveness and performance of the proposed algorithm.

Conclusions:

The novel conjugate gradients algorithm offers a substantial improvement in computational efficiency for RF pulse design.
This method simplifies the design process by removing the dependency on selecting the optimal regularization parameter.
The approach is particularly beneficial for multi-dimensional RF pulse design in the small flip angle regime, enhancing MRI techniques.