Objective: To calibrate 1.5 tesla magnetic resonance scanners for the quantification of the concentration of iron in the liver.
Material And Methods: We analyzed twenty-eight 1.5 tesla magnetic resonance scanners using a phantom with four tubes containing different concentrations of iron (III) chloride and one tube without iron. The phantom represented two typical patients: one with moderate iron overload and one with high iron overload. We measured the signal intensity ratio between each iron-containing tube and the tube without iron; then we calculated the theoretical levels of iron concentration in each scanner according to the model for the two levels of overload. We compared the results of each scanner with those of the reference scanner in which the model and the phantom had been designed, and we calculated the percentage of difference between the two scanners.
Results: The mean difference in the ratios compared to the reference center was 11% (0.3-39). The mean concentration of iron was 71 μmol Fe/g for moderate overload and 193 μmol Fe/g for high overload. The mean difference was 6% (1.2- 7%) and 3.4% (0-16%). respectively. In two scanners, we applied a correction factor so that the difference was below 25% in all cases.
Conclusion: We calibrated twenty-eight 1.5 tesla scanners for the concentration of iron in the liver and achieved variability less than 25%.
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http://dx.doi.org/10.1016/j.rx.2010.12.010 | DOI Listing |
Jpn J Radiol
January 2025
Department of Biomedical Imaging, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia.
Magnetic Resonance Imaging (MRI) safety is a critical concern in the Asia-Oceania region, as it is elsewhere in the world, due to the unique and complex MRI environment that demands attention. This call-for-action outlines ten critical steps to enhance MRI safety and promote a culture of responsibility and accountability in the Asia-Oceania region. Key focus areas include strengthening education and expertise, improving quality assurance, fostering collaboration, increasing public awareness, and establishing national safety boards.
View Article and Find Full Text PDFBiomol NMR Assign
January 2025
High Magnetic Field Laboratory, Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, China.
PhoCl is a photocleavable protein engineered from a green-to-red photoconvertible fluorescent protein by circular permutation, and has been used in various optogenetic applications including precise control of protein localization and activity in cells. Upon violet light illumination, PhoCl undergoes a β-elimination reaction to be cleaved at the chromophore, resulting in spontaneous dissociation into a large empty barrel and a small C-terminal peptide. However, the structural determinants and the mechanism of the PhoCl photocleavage remain elusive, hindering the further development of more robust photocleavable optogenetic tools.
View Article and Find Full Text PDFBrain Struct Funct
January 2025
Department of Biomedical Engineering, College of Chemistry and Life Sciences, Beijing University of Technology, Beijing, 100124, China.
The brain undergoes atrophy and cognitive decline with advancing age. The utilization of brain age prediction represents a pioneering methodology in the examination of brain aging. This study aims to develop a deep learning model with high predictive accuracy and interpretability for brain age prediction tasks.
View Article and Find Full Text PDFEur Child Adolesc Psychiatry
January 2025
Department of Child and Adolescent Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
While impaired response inhibition has been reported in attention-deficit/hyperactivity disorder (ADHD), findings in disruptive behavior disorders (DBDs) have been inconsistent, probably due to unaccounted effects of co-occurring ADHD in DBD. This study investigated the associations of behavioral and neural correlates of response inhibition with DBD and ADHD symptom severity, covarying for each other in a dimensional approach. Functional magnetic resonance imaging data were available for 35 children and adolescents with DBDs (8-18 years old, 19 males), and 31 age-matched unaffected controls (18 males) while performing a performance-adjusted stop-signal task.
View Article and Find Full Text PDFUltrasound Obstet Gynecol
January 2025
Decision and Bayesian Computation, Neuroscience & Computational Biology Departments, CNRS UMR 3571, Institut Pasteur, Paris, France.
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