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Configuration space representation of MRI sequences.
1School of Medicine, Department of Diagnostic and Interventional Radiology, Klinikum rechts der Isar der TUM, Technical University of Munich, Munich, Germany.
Magnetic Resonance in Medicine
|November 26, 2021
Summary
The continuous configuration model (CCM) offers a new way to understand MRI signal contrast, especially with unbalanced gradients. This method simplifies complex MRI sequences by treating them as a signal processing problem.
Area of Science:
- Magnetic Resonance Imaging (MRI)
- Spin Physics
- Signal Processing
Background:
- Local solutions in MRI offer limited insight into contrast generated by unbalanced gradients.
- A new approach is needed to formalize signal localization and address these limitations.
Purpose of the Study:
- To introduce the continuous configuration model (CCM) for a comprehensive understanding of MRI signal contrast.
- To overcome limitations of local solutions in MRI sequences with unbalanced gradients.
Main Methods:
- The CCM decomposes spin density using Fourier integrals, separating intrinsic tissue properties from gradient and off-resonance effects.
- Local dynamic equations are transformed into differential equations between configurations within the CCM framework.
Main Results:
- The CCM extends the EPG formalism to arbitrary MRI sequences, enabling rigorous treatment of signal localization, inhomogeneous broadening, and motion.
- A link between SWIFT and SSFP sequences was identified when applying CCM to frequency-swept NMR.
Conclusions:
- The CCM provides a signal processing viewpoint for analyzing MRI sequences.
- This approach may streamline the development and optimization of novel MRI imaging strategies.
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