A Fieldmap-Driven Few-Channel Shim Coil Design for MRI of the Human Brain - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physics in Medicine and Biology Année : 2020

A Fieldmap-Driven Few-Channel Shim Coil Design for MRI of the Human Brain

Résumé

We exploit the inter-subject similarity of inhomogeneous static magnetic field patterns arising in the human brain under MRI examination to design a small set of shim coils providing performance equivalent to numerous coils based on high-order Spherical Harmonics corrections. A hundred brain B 0-maps were first collected at 3 T. Ideal subject-specific electric current density stream functions are then computed with low power constraints, on a cylindrical surface. This step is repeated over tens of brain maps so that a Principal Component Analysis can be applied to the stream functions; the main components result in the small set of coils. Both 50-subject hold-out and 10-fold cross-validation are employed to evaluate consistency of the proposed system performance over a posteriori subjects. Simulations show that only 3 cylindrical coils manage to capture the principal magnetic field profiles in the human brain, thus providing a better static field inhomogeneity mitigation than that obtained from 16 unlimited-power high-order Spherical Harmonics coils, with inhomogeneity greatly reduced in the pre-frontal cortex compared to 2 nd-order shimmed baseline field acquisitions. The approach provides a very reduced channel count system for mitigating complex B 0-inhomogeneity patterns. Thus, a compact, cost-effective system could be conceived and driven by relatively low-budget electronics. The method should therefore have a strong impact in both Ultra-High and portable low-field MRI/MRS. Moreover, this technique can be applied to the design of shim coils addressing anatomies other than the brain. Keywords: B 0 inhomogeneity, human brain shimming, MRI, shim coil design, stream functions, Ultra-High-Field MRI, whole brain shimming.
Fichier principal
Vignette du fichier
IOP_Novel_Shim_Design.pdf (8.59 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-02966966 , version 1 (14-10-2020)

Identifiants

Citer

Bruno Pinho Meneses, Alexis Amadon. A Fieldmap-Driven Few-Channel Shim Coil Design for MRI of the Human Brain. Physics in Medicine and Biology, In press, ⟨10.1088/1361-6560/abc810⟩. ⟨hal-02966966⟩
75 Consultations
177 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More