A multi-inversion multi-echo spin and gradient echo echo planar imaging sequence with low image distortion for rapid quantitative parameter mapping and synthetic image contrasts
Autor: | Maaike van den Boomen, Berkin Bilgic, Daniel J. Park, Kawin Setsompop, Merlin J. Fair, Mary Kate Manhard, Jason P. Stockmann, SoHyun Han, Congyu Liao, Jon Polimeni |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Sequence
Shuffling Computer science Echo-Planar Imaging Resolution (electron density) Acceleration ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION Brain Shim (magnetism) quantitative mapping Inversion (discrete mathematics) Article synthetic imaging 030218 nuclear medicine & medical imaging Weighting 03 medical and health sciences 0302 clinical medicine Distortion Image Processing Computer-Assisted low distortion EPI Radiology Nuclear Medicine and imaging multi-shot acquisitions Algorithm 030217 neurology & neurosurgery |
Zdroj: | Magnetic resonance in medicine, 86(2), 866-880. Wiley Magn Reson Med |
ISSN: | 0740-3194 |
Popis: | Purpose: Brain imaging exams typically take 10-20 min and involve multiple sequential acquisitions. A low-distortion whole-brain echo planar imaging (EPI)-based approach was developed to efficiently encode multiple contrasts in one acquisition, allowing for calculation of quantitative parameter maps and synthetic contrast-weighted images.Methods: inversion prepared spin- and gradient-echo EPI was developed with sliceorder shuffling across measurements for efficient acquisition with T-1, T-2, and T-2* weighting. A dictionary-matching approach was used to fit the images to quantitative parameter maps, which in turn were used to create synthetic weighted images with typical clinical contrasts. Dynamic slice-optimized multi-coil shimming with a B-0 shim array was used to reduce B-0 inhomogeneity and, therefore, image distortion by >50%. Multi-shot EPI was also implemented to minimize distortion and blurring while enabling high in-plane resolution. A low-rank reconstruction approach was used to mitigate errors from shot-to-shot phase variation.Results: The slice-optimized shimming approach was combined with in-plane parallel-imaging acceleration of 4x to enable single-shot EPI with more than eightfold distortion reduction. The proposed sequence efficiently obtained 40 contrasts across the whole-brain in just over 1 min at 1.2 x 1.2 x 3 mm resolution. The multishot variant of the sequence achieved higher in-plane resolution of 1 x 1 x 4 mm with good image quality in 4 min. Derived quantitative maps showed comparable values to conventional mapping methods.Conclusion: The approach allows fast whole-brain imaging with quantitative parameter maps and synthetic weighted contrasts. The slice-optimized multi-coil shimming and multi-shot reconstruction approaches result in minimal EPI distortion, giving the sequence the potential to be used in rapid screening applications. |
Databáze: | OpenAIRE |
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