Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine
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To map the cerebral metabolic rate of oxygen (CMRO2 ) by estimating the oxygen extraction fraction (OEF) from gradient echo imaging (GRE) using phase and magnitude of the GRE data. ⋯ Quantitative CMRO2 mapping that fits the entire complex GRE data is feasible by combining QSM analysis of phase and qBOLD analysis of magnitude.
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To obtain multicontrast images including fat-suppressed contrast image, a novel multicontrast imaging method using an SSFP sequence with alternating RF flip angles is proposed. ⋯ The proposed method can be a useful tool for clinical diagnosis, such as the cartilage segmentation and the fast screening of lesions.
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Indirect 13 C MRS by proton-observed carbon editing (POCE) is a powerful method to study brain metabolism. The sensitivity of POCE-MRS can be enhanced through the use of short TEs, which primarily minimizes homonuclear J-evolution related losses; previous POCE-MRS implementations use longer than optimal echo times due to sequence limitations, or short TE image selected in vivo spectroscopy-based multi-shot acquisitions for 3D localization. To that end, this paper presents a novel single-shot point resolved spectroscopy (PRESS)-localized POCE-MRS sequence that involves the application of simultaneous editing and localization pulses (SEAL)-PRESS, allowing the TE to be reduced to a theoretically optimal value of ∼ 1/JHC . ⋯ We report for the first time, a single-shot PRESS-localized and edited 8.1-ms TE POCE-MRS sequence with optimal sensitivity, editing efficiency, and localization.
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To develop a volumetric imaging technique with 0.8-mm isotropic resolution and 10-s/volume rate to detect and analyze breast lesions in a bilateral, dynamic, contrast-enhanced MRI exam. ⋯ The STELLR reconstruction approach of 3D radial sampling with mask subtraction provides a high-performance imaging technique for characterizing enhancing structures within the breast. It is capable of maintaining temporal fidelity, while visualizing breast lesions with high detail over a large FOV to include both breasts.
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To reconstruct artifact-free images from measured k-space data, when the actual k-space trajectory deviates from the nominal trajectory due to gradient imperfections. ⋯ The proposed method provides a general framework for the recovery of artifact-free images from radial trajectories without the need for trajectory calibration.