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Purpose: To demonstrate a rapid MR technique that combines imaging and R2* mapping based on a single radial multi-gradient-echo (rMGE) data set. The technique provides a fast method for online monitoring of the administration of (super-)paramagnetic contrast agents as well as image-guided drug delivery.
Materials And Methods: Data are acquired using an rMGE sequence, resulting in interleaved undersampled radial k-spaces representing different echo times (TEs). These data sets are reconstructed separately, yielding a series of images with different TEs used for pixelwise R2* mapping. A fast numerical algorithm implemented on a real-time reconstruction platform provides online estimation of the relaxation rate R2*. Simultaneously the images are summed for the computation of a high-resolution image.
Results: Convenient high-resolution R2* maps of phantoms and the liver of a healthy volunteer were obtained. In addition to stable intrinsic baseline maps, the proposed technique provides particularly accurate results for the high relaxation rates observed during the presence of (super-)paramagnetic contrast agents. Assuming that the change in R2* is proportional to the concentration of the agent, the technique offers a rough estimate for dynamic dosage.
Conclusion: The simultaneous online display of morphological and parametric information permits convenient, quantitative surveillance of contrast-agent administration.
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http://dx.doi.org/10.1002/jmri.20712 | DOI Listing |
Brain
September 2025
Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, 13005 Marseille, France.
The lateral prefrontal cortex (LPFC) serves as a critical hub for higher-order cognitive and executive functions in the human brain, coordinating brain networks whose disruption has been implicated in many neurological and psychiatric disorders. While transcranial brain stimulation treatments often target the LPFC, our current understanding of connectivity profiles guiding these interventions based on electrophysiology remains limited. Here, we present a high-resolution probabilistic map of bidirectional effective connectivity between the LPFC and widespread cortical and subcortical regions.
View Article and Find Full Text PDFJBMR Plus
October 2025
Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, 6009, Australia.
Genome-wide association studies (GWAS) relevant to osteoporosis have identified hundreds of loci; however, understanding how these variants influence the phenotype is complicated because most reside in non-coding DNA sequence that serves as transcriptional enhancers and repressors. To advance knowledge on these regulatory elements in osteoclasts (OCs), we performed Micro-C analysis, which informs on the genome topology of these cells and integrated the results with transcriptome and GWAS data to further define loci linked to BMD. Using blood cells isolated from 4 healthy participants aged 31-61 yr, we cultured OC in vitro and generated a Micro-C chromatin conformation capture dataset.
View Article and Find Full Text PDFErgonomics
September 2025
School of Mechanical Engineering, North University of China, Taiyuan, China.
Ergonomics increasingly emphasises that seat design should align with the driver's physiological needs to enhance comfort and health. This study uses deep learning to evaluate the impact of seat multi-axis coherent vibration on driver comfort. Through road tests, the multi-axis vibration signals were collected from the seat backrest, cushion and floor, simultaneously collecting subjective evaluation data.
View Article and Find Full Text PDFPLoS One
September 2025
Perennial Climate Inc., Boulder, Colorado, United States of America.
Voluntary carbon market (VCM) programs in agriculture depend on accurate measurements of soil organic carbon (SOC) that can be deployed at scale efficiently, but barriers are preventing widespread adoption. To overcome these challenges, we developed a digital soil mapping (DSM) framework driven by machine-learning and numerous spatial covariates, including long-term climate proxies, short-term climate and weather-related variables, topographic and edaphic measurements, and remote sensing time-series summaries. We show that the model can predict SOC content in the top 30 cm of soil using 5,230 measurements of SOC in agricultural land within 47 states in the contiguous United States (CONUS).
View Article and Find Full Text PDFMagn Reson Med
September 2025
Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Purpose: To implement, optimize, and validate parallel imaging (PI)-accelerated, 2D, flip angle modulated (FAM) chemical shift-encoded quantification of liver proton-density fat fraction (PDFF), with motion insensitivity.
Methods: The optimization cost function that determines flip angles in FAM was generalized for PI. Phantom studies and prospective studies in volunteers with varying liver fat levels were performed.