Purpose: The aim of this work is to derive a theoretical framework for quantitative noise and temporal fidelity analysis of time-resolved k-space-based parallel imaging methods.
Theory: An analytical formalism of noise distribution is derived extending the existing g-factor formulation for nontime-resolved generalized autocalibrating partially parallel acquisition (GRAPPA) to time-resolved k-space-based methods. The noise analysis considers temporal noise correlations and is further accompanied by a temporal filtering analysis.
Methods: All methods are derived and presented for k-t-GRAPPA and PEAK-GRAPPA. A sliding window reconstruction and nontime-resolved GRAPPA are taken as a reference. Statistical validation is based on series of pseudoreplica images. The analysis is demonstrated on a short-axis cardiac CINE dataset.
Results: The superior signal-to-noise performance of time-resolved over nontime-resolved parallel imaging methods at the expense of temporal frequency filtering is analytically confirmed. Further, different temporal frequency filter characteristics of k-t-GRAPPA, PEAK-GRAPPA, and sliding window are revealed.
Conclusion: The proposed analysis of noise behavior and temporal fidelity establishes a theoretical basis for a quantitative evaluation of time-resolved reconstruction methods. Therefore, the presented theory allows for comparison between time-resolved parallel imaging methods and also nontime-resolved methods. Magn Reson Med 74:125-135, 2015. © 2014 Wiley Periodicals, Inc.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/mrm.25386 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Estimating Human Fat and Muscle Conductivity From 100 Hz to 1 MHz Using Measurements and Modelling.
Bioelectromagnetics
January 2025
Seibersdorf Labor GmbH, Seibersdorf, Austria.
The electrical conductivity of human tissues is a major source of uncertainty when modelling the interactions between electromagnetic fields and the human body. The aim of this study is to estimate human tissue conductivities in vivo over the low-frequency range, from 30 Hz to 1 MHz. Noninvasive impedance measurements, medical imaging, and 3D surface scanning were performed on the forearms of ten volunteer test subjects.
View Article and Find Full Text PDFTagGen: Diffusion-based generative model for cardiac MR tagging super resolution.
Magn Reson Med
January 2025
Department of Radiology, University of Missouri, Columbia, Missouri, USA.
Purpose: The aim of the work is to develop a cascaded diffusion-based super-resolution model for low-resolution (LR) MR tagging acquisitions, which is integrated with parallel imaging to achieve highly accelerated MR tagging while enhancing the tag grid quality of low-resolution images.
Methods: We introduced TagGen, a diffusion-based conditional generative model that uses low-resolution MR tagging images as guidance to generate corresponding high-resolution tagging images. The model was developed on 50 patients with long-axis-view, high-resolution tagging acquisitions.
Simultaneous multislice diffusion imaging using navigator-free multishot spiral acquisitions.
Magn Reson Med
January 2025
Center for Biomedical Imaging Research, School of Biomedical Engineering, Tsinghua University, Beijing, China.
Purpose: This work aims to raise a novel design for navigator-free multiband (MB) multishot uniform-density spiral (UDS) acquisition and reconstruction, and to demonstrate its utility for high-efficiency, high-resolution diffusion imaging.
Theory And Methods: Our design focuses on the acquisition and reconstruction of navigator-free MB multishot UDS diffusion imaging. For acquisition, radiofrequency-pulse encoding was used to achieve controlled aliasing in parallel imaging in MB imaging.
Anatomical investigation of safety determining factors for keyhole drilling trajectories for robotic cochlear implant surgery.
Eur Arch Otorhinolaryngol
January 2025
Vrije Universiteit Brussel, Brussels Health Centre, Brussels, Belgium.
Purpose: Cochlear implants (CI) are the most successful bioprosthesis in medicine probably due to the tonotopic anatomy of the auditory pathway and of course the brain plasticity. Correct placement of the CI arrays, respecting the inner ear anatomy are therefore important. The ideal trajectory to insert a cochlear implant array is defined by an entrance through the round window membrane and continues as long as possible parallel to the basal turn of the cochlea.
View Article and Find Full Text PDFEarly gross motor performance is associated with concurrent prelinguistic and social development.
Pediatr Res
January 2025
Department of Physiology, University of Helsinki, Helsinki, Finland.
Background: To study how early gross motor development links to concurrent prelinguistic and social development.
Methods: We recruited a population-based longitudinal sample of 107 infants between 6 and 21 months of age. Gross motor performance was quantified using novel wearable technology for at-home recordings of infants' spontaneous activity.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!