Central nervous system abnormalities in fetuses are fairly common, happening in 0.1% to 0.2% of live births and in 3% to 6% of stillbirths.
View Article and Find Full Text PDFJ Appl Clin Med Phys
November 2018
The attenuation of 511 keV photons by the structure of a PET/MR scanner was measured prior to energizing the magnet. The exposure rate from a source of fluorine-18 was measured in air and, with the source placed at the isocenter of the instrument, at various points outside of the scanner. In an arc from 45 to 135 degrees relative to the long axis of the scanner and at a distance of 1.
View Article and Find Full Text PDFIntroduction: In the era of precision medicine, quantitative applications of x-ray Computed Tomography (CT) are on the rise. These require accurate measurement of the CT number, also known as the Hounsfield Unit. In this study, we evaluated the effect of patient attenuation-induced beam hardening of the x-ray spectrum on the accuracy of the HU values and a strategy to correct for the resulting deviations in the measured HU values.
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