Quantitative computed tomography provides the most accurate form of bone mineral density measurement. It is very useful in several applications when used with micro computed tomography (microCT). The objective of this study is to evaluate the quantitative capability of iterative and analytic reconstruction with and without energy-based beam hardening calibration using a home-made microCT. Due to the fact that the source of X-rays in the microCT is poly-energetic and the linear attenuation coefficient varies with the energy of the X-ray photons, a specific correction is presented in this study that resolves the poly-energetic effect. Then, a 3D distribution of the linear attenuation coefficient is reconstructed from the ordered subsets using the maximum likelihood and T-FDK algorithms. These algorithms were both developed for cone-beam microCT. The images reconstructed by the two algorithms with/without correction are presented. A region of interest analysis is used to evaluate the results from two algorithms and their advantages and disadvantages are discussed. The quantitative capability is better when the image is reconstructed using the iterative method along with a beam hardening correction.
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http://dx.doi.org/10.1016/j.compmedimag.2006.09.007 | DOI Listing |
Hum Fertil (Camb)
December 2025
Instituto Superior Miguel Torga, Coimbra, Portugal.
Infertility is increasing globally, affecting one in six adults due to factors like delayed childbearing and lifestyle changes. Despite the recognition of the importance of increasing fertility awareness, levels remain low. This study evaluated the perceptions of 'FActs!', a serious game aimed at improving adolescents' fertility awareness.
View Article and Find Full Text PDFConf Proc Int Conf Image Form Xray Comput Tomogr
August 2024
Department of Radiology, Perelman School of Medicine, Philadelphia, PA USA.
Despite the evident benefits of spectral computed tomography (CT) in delivering qualitative imaging superior to that of conventional CT in adults, its application in pediatric diagnostic imaging is still relatively limited due to various reasons, including design limitations and radiation dose considerations. The use of specialized K-edge filters, in conjunction with other spectral technologies, has been demonstrated to improve spectral quantification accuracy. X-ray flux limitations generally pose challenges in these concepts when applied to adults.
View Article and Find Full Text PDFActa Radiol
January 2025
Department of Radiology, Zhongshan Hospital (Xiamen), Fudan University, Xiamen, PR China.
Background: Early detection of changes in lumbar intervertebral disc degeneration (IVDD) has great clinical significance. T1rho and UTE-T2* relaxometry are capable of providing information about biochemical changes in IVDD. However, they have not been previously analyzed and compared directly in the same patients.
View Article and Find Full Text PDFActa Biochim Biophys Sin (Shanghai)
January 2025
CAS Key Laboratory of Synthetic Biology, CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences (CAS), Shanghai 200032, China.
U32 is an industrial strain capable of producing therapeutically useful rifamycin SV. In early days of fermentation studies, nitrate was found to increase the yield of rifamycin along with globally, affecting both carbon and nitrogen metabolism in favor of antibiotic biosynthesis; thus, the (NSE) hypothesis was proposed. Although GlnR is likely the master regulator of the pleotropic effect of NSE, the global metabolism affected by NSE has never been systematically examined.
View Article and Find Full Text PDFPLoS One
January 2025
LP2N, Laboratoire Photonique Numérique et Nanosciences, University Bordeaux, Talence, France.
Recent advances in bioengineering have made it possible to develop increasingly complex biological systems to recapitulate organ functions as closely as possible in vitro. Monitoring the assembly and growth of multi-cellular aggregates, micro-tissues or organoids and extracting quantitative information is a crucial but challenging task required to decipher the underlying morphogenetic mechanisms. We present here an imaging platform designed to be accommodated inside an incubator which provides high-throughput monitoring of cell assemblies over days and weeks.
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