TranSMS: Transformers for Super-Resolution Calibration in Magnetic Particle Imaging

TL;DR

This paper introduces TranSMS, a deep learning method using Transformers to super-resolve system matrices in magnetic particle imaging, enabling faster calibration and improved image reconstruction.

Contribution

The paper presents a novel Transformer-based deep learning approach for accelerated MPI calibration through super-resolution of system matrices.

Findings

TranSMS achieves up to 64-fold acceleration in 2D MPI imaging.

It significantly improves system matrix recovery and image reconstruction quality.

Demonstrations on simulated and experimental data validate its effectiveness.

Abstract

Magnetic particle imaging (MPI) offers exceptional contrast for magnetic nanoparticles (MNP) at high spatio-temporal resolution. A common procedure in MPI starts with a calibration scan to measure the system matrix (SM), which is then used to set up an inverse problem to reconstruct images of the MNP distribution during subsequent scans. This calibration enables the reconstruction to sensitively account for various system imperfections. Yet time-consuming SM measurements have to be repeated under notable changes in system properties. Here, we introduce a novel deep learning approach for accelerated MPI calibration based on Transformers for SM super-resolution (TranSMS). Low-resolution SM measurements are performed using large MNP samples for improved signal-to-noise ratio efficiency, and the high-resolution SM is super-resolved via model-based deep learning. TranSMS leverages a vision transformer module to capture contextual relationships in low-resolution input images, a dense convolutional module for localizing high-resolution image features, and a data-consistency module to ensure measurement fidelity. Demonstrations on simulated and experimental data indicate that TranSMS significantly improves SM recovery and MPI reconstruction for up to 64-fold acceleration in two-dimensional imaging.