Motion‐insensitive diffusion imaging of the brain using optical tracking and dynamic sequence updates
Year: 2021
Type: article
Abstract: PURPOSE: Diffusion-weighted imaging (DWI) is sensitive to head movements, which may cause signal losses because of motion-induced gradient imbalances. Prospective motion correction using fast optical tracking can attenuate these artifacts. Approaches include quasicontinuous updates of gradients and radiofrequency (RF) pulses or dynamically applying a rebalancing gradient to restore the gradient balance, but these prior methods used bipolar diffusion gradients. The goal of this project was to develop and evaluate a motion-insensitive implementation for the more common monopolar diffusion sequence. METHODS: and rotational velocities up to 20°/s. Motion sensitivity, signal losses, and in vivo image profiles were compared between scans with and without intrasequence motion updates. RESULTS: With typical motion parameters, intrasequence motion updates with optimal parameters reduced the motion sensitivity of DWI (motion-induced gradient moment imbalance) sevenfold. Optimal results were achieved by matching the echo time of the pulse sequence to an even multiple of the tracking system frame-to-frame period. Average signal losses and the frequency of signal dropouts in phantom and in vivo measurements were reduced when intrasequence updates were enabled, and quality measures of DTI analyses were improved. CONCLUSION: A correction scheme for the monopolar DWI sequence can reduce the motion sensitivity of brain DWI up to sevenfold compared with an implementation without intrasequence updates.
Source: Magnetic Resonance in Medicine
DOI: 10.1002/mrm.28747
Authors: Artan Kaso, Thomas Ernst
Institution: University of Maryland, Baltimore
Language: English
Subfield: Radiology, Nuclear Medicine and Imaging
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: National Institute on Drug Abuse
OpenAlex ID: W3137965456