We report the design, construction, and initial tests of a hyperpolariser to produce polarised Xe and He gas for medical imaging of the lung. The hyperpolariser uses the Spin-Exchange Optical Pumping method to polarise the nuclear spins of the isotopic gas. Batch mode operation was chosen for the design to produce polarised Xe and polarised He. Two-side pumping, electrical heating and a piston to transfer the polarised gas were some of the implemented techniques that are not commonly used in hyperpolariser designs. We have carried out magnetic resonance imaging experiments demonstrating that the He and Xe polarisation reached were sufficient for imaging, in particular for in vivo lung imaging using Xe. Further improvements to the hyperpolariser have also been discussed.
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http://dx.doi.org/10.1016/j.mri.2021.02.010 | DOI Listing |
Comput Biol Med
January 2025
College of Physics and Electronic Information Engineering, Zhejiang Normal University, Jinhua, 321004, China; Zhejiang Institute of Optoelectronics, Jinhua, 321004, China. Electronic address:
Accurate segmentation of brain tumors from MRI scans is a critical task in medical image analysis, yet it remains challenging due to the complex and variable nature of tumor shapes and sizes. Traditional convolutional neural networks (CNNs), while effective for local feature extraction, struggle to capture long-range dependencies crucial for 3D medical image analysis. To address these limitations, this paper presents VcaNet, a novel architecture that integrates a Vision Transformer (ViT) with a fusion channel and spatial attention module (CBAM), aimed at enhancing 3D brain tumor segmentation.
View Article and Find Full Text PDFJ Radiol Prot
January 2025
Department of Biostatistics, Soon Chun Hyang University Hospital Bucheon, Bucheon, Gyeonggi-do, Korea (the Republic of).
This study investigated the additional radiation exposure, influencing factors, and clinical significance of overlapping Z-axis coverage in abdominopelvic CT scans performed consecutively after same-day chest CT scans. Data from 761 patients were analyzed, with measuring the total and overlapping Z-axis coverage of the portal venous phase in abdominopelvic CT scans. The average overlapping portion was 33.
View Article and Find Full Text PDFN Engl J Med
January 2025
From the Department of Medicine, University of Auckland, Auckland, New Zealand (M.J.B., Z.N., A.M., C.G., V.P., B.M., A.G., I.R.R., G.G., A.H.); the Department of Psychology, Stanford University, Stanford, CA (C.G.); and the Department of Radiology, Starship Hospital, Auckland, New Zealand (S.B.).
Background: Zoledronate prevents fractures in older women when administered every 12 to 18 months, but its effects on bone density and bone turnover persist beyond 5 years. Whether infrequent zoledronate administration would prevent vertebral fractures in early postmenopausal women is unknown.
Methods: We conducted a 10-year, prospective, double-blind, randomized, placebo-controlled trial involving early postmenopausal women (50 to 60 years of age) with bone mineral density T scores lower than 0 and higher than -2.
Leuk Lymphoma
January 2025
Endocrinology Division, Hospital for Special Surgery, New York, NY, USA.
Neurology
February 2025
Division of Clinical and Metabolic Genetics, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada.
Pathogenic variants in cause congenital muscular dystrophy through hypoglycosylation of alpha-dystroglycan (OMIM #615350). The established phenotypic spectrum of GMPPB-related disorders includes recurrent rhabdomyolysis, limb-girdle muscular dystrophy, neuromuscular transmission abnormalities, and congenital muscular dystrophy with variable brain and eye anomalies. We report a 9-month-old male infant with congenital muscular dystrophy, infantile spasms, and compound heterozygous pathogenic variants (c.
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