Related Experiment Video
Updated: Feb 28, 2026
17:16
Registered Bioimaging of Nanomaterials for Diagnostic and Therapeutic Monitoring
Published on: December 9, 2010
10.9K
Diffusion Weighted Fast Spin Echo With RF-Encoded Slabs for Portable Low-Field MRI Systems
Philip K Lee1, Yueqi Qiu1, Suen Chen1
1School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Magnetic Resonance in Medicine
|February 25, 2026
Summary
A new diffusion-weighted fast spin echo (DW-FSE) technique offers distortionless, high-SNR imaging on portable MRI systems. This robust method achieves clinically feasible scan times, improving diagnostic capabilities in low-field MRI environments.
Area of Science:
- Magnetic Resonance Imaging
- Diffusion Weighted Imaging
- Medical Device Technology
Background:
- Portable MRI systems offer accessibility but face challenges in image quality and scan time for advanced sequences.
- Diffusion Weighted Imaging (DWI) is crucial for neurological assessment, but conventional methods like Echo Planar Imaging (EPI) are prone to artifacts and hardware demands.
- Developing robust DWI techniques for low-field portable MRI is essential for expanding its clinical utility.
Purpose of the Study:
- To develop a robust diffusion-weighted (DW) acquisition technique for portable MRI systems.
- To achieve clinically feasible scan times for DW imaging on low-field systems.
- To overcome limitations of existing DWI methods in portable MRI settings.
Main Methods:
- A linear reconstruction model was developed for slab diffusion-weighted fast spin echo (DW-FSE) data, incorporating tailored RF-encoding, motion-induced phases, and systematic phase errors.
- Systematic phase errors were calibrated using a phantom, and the DW-FSE technique was compared to DW-EPI in vivo on a 110 mT portable system.
- Retrospective undersampling was used to evaluate image quality and diffusivity variation within clinically feasible scan times.
Main Results:
- The developed RF-encoded slab DW-FSE technique produced trace-weighted images free from distortion artifacts and with 5x smaller voxel sizes compared to DW-EPI.
- Accurate estimation of motion-induced phases and reduction of ghosting artifacts were achieved by accounting for various phase sources.
- A scan time of 12 minutes allowed for 12 cm slice coverage with 2.5x2.5x5 mm³ voxel sizes, demonstrating potential for clinical feasibility.
Conclusions:
- Diffusion-weighted FSE is a robust and distortionless approach for high signal-to-noise ratio (SNR) efficiency DWI on portable MRI systems.
- This multiband quadratic phase increment DW-FSE technique effectively utilizes low-field strengths, offering advantages over DW-EPI in terms of SAR, peak B1, and hardware dependency.
Related Concept Videos
01:24Magnetic Resonance Imaging
10.1K
Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI...
10.1K
01:17NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences
1.9K
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
1.9K