Highly accelerated submillimeter resolution 3D GRASE with controlled blurring in ‐weighted functional MRI at 7 Tesla: A feasibility study
| العنوان: | Highly accelerated submillimeter resolution 3D GRASE with controlled blurring in ‐weighted functional MRI at 7 Tesla: A feasibility study |
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| المؤلفون: | David A. Feinberg, Salvatore Torrisi, Suhyung Park, Alexander Beckett, Jennifer Townsend |
| المصدر: | Magnetic Resonance in Medicine. 85:2490-2506 |
| بيانات النشر: | Wiley, 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Reduction (complexity), Physics, Point spread function, Full width at half maximum, Nuclear magnetic resonance, Aliasing, Modulation, Resolution (electron density), Spin echo, Radiology, Nuclear Medicine and imaging, Sensitivity (control systems) |
| الوصف: | Purpose To achieve highly accelerated submillimeter resolution T 2 -weighted functional MRI at 7T by developing a three-dimensional gradient and spin echo imaging (GRASE) with inner-volume selection and variable flip angles (VFA). Methods GRASE imaging has disadvantages in that (a) k-space modulation causes T 2 blurring by limiting the number of slices and (b) a VFA scheme results in partial success with substantial SNR loss. In this work, accelerated GRASE with controlled T 2 blurring is developed to improve a point spread function (PSF) and temporal signal-to-noise ratio (tSNR) with a large number of slices. To this end, the VFA scheme is designed by minimizing a trade-off between SNR and blurring for functional sensitivity, and a new GRASE-optimized random encoding, which takes into account the complex signal decays of T 2 and T 2 ∗ weightings, is proposed by achieving incoherent aliasing for constrained reconstruction. Numerical and experimental studies were performed to validate the effectiveness of the proposed method over regular and VFA GRASE (R- and V-GRASE). Results The proposed method, while achieving 0.8 mm isotropic resolution, functional MRI compared to R- and V-GRASE improves the spatial extent of the excited volume up to 36 slices with 52%-68% full width at half maximum (FWHM) reduction in PSF but approximately 2- to 3-fold mean tSNR improvement, thus resulting in higher BOLD activations. Conclusions We successfully demonstrated the feasibility of the proposed method in T 2 -weighted functional MRI. The proposed method is especially promising for cortical layer-specific functional MRI. |
| تدمد: | 1522-2594 0740-3194 |
| DOI: | 10.1002/mrm.28589 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::fa70a734382f66d70fba88a3ab1d1cd2 https://doi.org/10.1002/mrm.28589 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi...........fa70a734382f66d70fba88a3ab1d1cd2 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 15222594 07403194 |
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| DOI: | 10.1002/mrm.28589 |