Unlabelled: SPECT/CT has made it possible to perform attenuation correction easily. However, CT-based attenuation correction (CTAC) is overestimated when metal is inside the body. The aim of this investigation was to create and test a new attenuation correction formula for CTAC that decreases the overestimation caused by an artificial femoral head and hip joint.
Methods: We tested the usefulness of the new formula in a phantom study. The phantom contained "bones" made from gypsum. The components were placed in the phantom, the point source was placed both near metal and away from metal, and the counts were compared to verify the usefulness of the new attenuation correction formula. The new formula included use of thresholds to prevent the overestimation caused by proximity to metal.
Results: With the standard formula, the maximum overestimation was 18% for a 22-cm artificial hip joint placed in the acetabular roof. With the new formula, using 2 thresholds, the overestimation decreased to 4%.
Conclusion: The new attenuation correction formula helps provide more correct data in SPECT/CT examinations of patients with metallic implants.
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http://dx.doi.org/10.2967/jnmt.113.121152 | DOI Listing |
Environ Sci Process Impacts
January 2025
Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, Parsons Laboratory, 15 Vassar Street, Cambridge, Massachusetts 02139, USA.
The high salinity and organic content in oil and gas wastewaters can cause ion suppression during liquid chromatography mass spectrometry (LC/MS) analysis, diminishing the sensitivity and accuracy of measurements in available methods. This suppression is severe for low molecular weight organic compounds such as ethanolamines (, monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), -methyldiethanolamine (MDEA), and ,-ethyldiethanolamine (EDEA)). Here, we deployed solid phase extraction (SPE), mixed-mode LC, triple quadrupole MS with positive electrospray ionization (ESI), and a suite of stable isotope standards (, one per target compound) to correct for ion suppression by salts and organic matter, SPE losses, and instrument variability.
View Article and Find Full Text PDFInt J Exerc Sci
December 2024
Exercise Science, Florida Southern College, Lakeland, FL, USA.
The purpose of the study was to compare heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) following high load resistance exercise (HLRE) and blood flow restriction exercise (BFRE) with a knee wrap (kBFRE) and pneumatic cuff (pBFRE). Eleven men (N = 9) and women (N = 2) participated. HR, SBP, and DBP were collected at Rest, immediately post exercise (IP), 10-, 30-, and 45-minutes post exercise.
View Article and Find Full Text PDFSci Rep
January 2025
Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, P. R. China.
Nanoscale Adv
December 2024
Department of Chemical Engineering, Sirjan University of Technology Sirjan Iran https://scholar.google.com/citations?user=N6z-rHsAAAAJ&hl=en.
The potential applicability of the C nanocage and its boron nitride-doped analogs (CBN and CBN) as pyrazinamide (PA) carriers was investigated using density functional theory. Geometry optimization and energy calculations were performed using the B3LYP functional and 6-31G(d) basis set. Besides, dispersion-corrected interaction energies were calculated at CAM (Coulomb attenuated method)-B3LYP/6-31G(d,p) and M06-2X/6-31G(d,p) levels of theory.
View Article and Find Full Text PDFNat Commun
January 2025
British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.
Cheek swabs, heterogeneous samples consisting primarily of buccal epithelial cells, are widely used in pediatric DNA methylation studies and biomarker creation. However, the decrease in buccal proportion with age in adults remains unexamined in childhood. We analyzed cheek swabs from 4626 typically developing children 2-months to 20-years-old.
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