Bias field correction of MPRAGE by an external reference -- The poor man's MP2RAGE
H. Olsson, G. Helms

TL;DR
This paper presents a simple, cost-effective method for bias field correction of MPRAGE images at 7T using an external reference, enabling semi-quantitative T1 mapping comparable to MP2RAGE with reduced scan time.
Contribution
It introduces a non-interleaved normalization approach for MPRAGE that simplifies bias correction and T1 mapping, reducing scan time while maintaining image quality.
Findings
Optimized flip angle at 3° for best contrast and SNR.
Reduced acquisition time by increasing reference voxel size with negligible bias.
Normalized WM segmentation variability decreased from 24% to 9%.
Abstract
Purpose: To implement and evaluate a sequential approach to obtain semi-quantitative T1-weighted MPRAGE images, unbiased by B1 inhomogeneities at 7T. Methods: In the reference gradient echo used for normalization of the MPRAGE image, flip angle (aGE) and acquisition voxel size (Vref) was varied to optimize tissue contrast and acquisition time (Tacq). The finalized protocol was implemented at three different resolutions and the reproducibility was evaluated. Maps of T1 were derived based on the normalized MPRAGE through forward signal modelling. Results: A good compromise between tissue contrast and SNR was reached at aGE=3{\deg}. A reduction of the reference GE Tacq by a factor of 4, at the cost of negligible bias, was obtained by increasing Vref with a factor of 8 relative the MPRAGE resolution. The coefficient-of-variation in segmented WM was 9+/-5% after normalization, compared…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
Taxonomy
TopicsMedical Imaging Techniques and Applications · Advanced MRI Techniques and Applications · Cardiac Imaging and Diagnostics
