Higher spatial resolution and sensitivity in whole brain functional MRI at 7T using 3D EPI accelerated with variable density CAIPI sampling and temporal random walk

Magnetic Resonance in Medicine, Journal Year: 2025, Volume and Issue: unknown

Published: April 24, 2025

Abstract Purpose To develop an efficient 3D EPI encoding technique for high spatiotemporal resolution functional MRI. Methods exploit fMRI data structure, we introduce a variable density 2D CAIPI sampling in the spatial domain combined with time‐wise extra random time domain, thus achieving pseudo‐regular regular blip while allowing incoherent complementary manner across time. This enabled temporally regularized reconstruction of highly accelerated acquisition. The scheme was then validated against invariant by applying to locally confined and whole‐brain around primary visual cortex, respectively, increasing resolutions. Results For partial brain imaging, our proposed method achieved higher accuracy, resulting substantial increase SSIM compared alternative 0.64 mm‐isotropic resolution. When used whole imaging at 0.56 resolution, showed decreased extent activation produced high‐quality images clear distinction between activated non‐activated regions calcarine fissure specificity. Conclusion scheme, which exploits coherent properties, can significantly improve image quality providing good balance sensitivity specificity regions.

Language: Английский

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Towards assessing and improving the reliability of ultrashort echo time quantitative magnetization transfer (UTE-qMT) MRI of cortical bone: In silico and ex vivo study

Magnetic Resonance Materials in Physics Biology and Medicine, Journal Year: 2024, Volume and Issue: 37(6), P. 983 - 992

Published: Aug. 10, 2024

Abstract Objective To assess and improve the reliability of ultrashort echo time quantitative magnetization transfer (UTE-qMT) modeling cortical bone. Materials Methods Simulation-based digital phantoms were created that mimic UTE-qMT properties bones. A wide range SNR from 25 to 200 was simulated by adding different levels noise synthesized MT-weighted images effect on fitting results. Tensor-based denoising algorithm applied These results phantom studies validated via ex vivo rat leg bone scans. Results The selection initial points for nonlinear number data tested qMT analysis have minimal result. Magnetization exchange rate measurements are highly dependent raw images, which can be substantially improved with an appropriate gives similar 8-fold higher SNR. Discussion approach enables assessment providing known ground truth. findings utilized optimizing acquisition pipeline imaging

Language: Английский

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Quantitative MRI Using Multiparametric Mapping

Springer eBooks, Journal Year: 2024, Volume and Issue: unknown, P. 239 - 261

Published: Jan. 1, 2024

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