A novel passive shimming optimization method of MRI magnet based on a PSA-SQP hybrid algorithm

In Magnetic Resonance Imaging (MRI), achieving a highly uniform main magnetic field (B 0 ) is essential for producing detailed images of human anatomy. Passive Shimming (PS) is a technique used to enhance B 0 uniformity by strategically arranging shimming iron pieces inside the magnet bore. Traditio...

Full description

Saved in:
Bibliographic Details
Published in:Scientific reports Vol. 15; no. 1; pp. 28419 - 10
Main Authors: Zhao, Jie, Zhu, Minhua, Xia, Ling, Fan, Yifeng, Liu, Feng
Format: Journal Article
Language:English
Published: London Nature Publishing Group UK 04.08.2025
Nature Publishing Group
Nature Portfolio
Subjects:
639/166
639/705
639/766
Algorithms
Humanities and Social Sciences
Hybrid optimization
Integer programming
Iron
Linear programming
Magnetic fields
Magnetic resonance imaging
multidisciplinary
NMR
Nuclear magnetic resonance
Optimization algorithms
Passive shimming
Pattern search algorithm
Regularization methods
Science
Science (multidisciplinary)
Sequential quadratic programming
Pattern search algorithm
Passive shimming
Magnetic resonance imaging
Sequential quadratic programming
Hybrid optimization
ISSN:2045-2322, 2045-2322
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:In Magnetic Resonance Imaging (MRI), achieving a highly uniform main magnetic field (B 0 ) is essential for producing detailed images of human anatomy. Passive Shimming (PS) is a technique used to enhance B 0 uniformity by strategically arranging shimming iron pieces inside the magnet bore. Traditionally, PS optimization has been implemented using Linear Programming (LP), posing challenges in balancing field quality with the quantity of iron used for shimming. This work aims to improve the efficacy of passive shimming by optimally balancing field quality, iron usage, and harmonics, leading to a smoother field profile. This study introduces a hybrid algorithm that combines a Pattern Search Algorithm with Sequential Quadratic Programming (PSA-SQP) to enhance shimming performance. Additionally, a regularization method is employed to effectively reduce the use of iron pieces. The magnetic field improved from 462 ppm to 6.7 ppm, utilizing merely 0.8 kg of iron in a 400 mm Diameter of Spherical Volume (DSV) of a 7T MRI magnet. Compared to traditional LP optimization techniques, this method notably enhanced magnetic field uniformity by 98.5% and reduced the iron weight requirement by 91.7%, showcasing impressive performance. The proposed new passive shimming algorithm is more effective in improving magnetic field uniformity for MRI applications.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
content type line 23
ISSN:2045-2322
2045-2322
DOI:10.1038/s41598-025-13751-4