This result points out that very large errors can occur in calculating Z(eff) from the values of μ if a fixed value for x is used. The importance of this result to dual energy computed tomography is pointed out and it is concluded that the proper values for x are required to be incorporated in the inversion algorithms, for the different regimes of Z(eff).
This simple and reliable method has the potential as an effective modality to investigate the composition of noncalcified coronary artery plaques and thus help in their characterization. In this inversion method, (ρ(e), Z(eff)) of the scanned sample can be found by eliminating the effects of the CT machine and also by ensuring that the determination of the two unknowns (ρ(e), Ze(ff)) does not interfere with each other and the nature of the plaque can be identified in terms of a three component model.
The present study has been dedicated to the synthesis of a new and highly stable computed tomography contrast agent based on pegylated deoxycholic acid-coated gold nanoparticles (DCA-PEG-GNPs) measuring 17 nm in size. To stabilize the gold nanoparticles (GNPs) as well as increasing their vascular retention time, polyethylene glycol, PEG, with a molecular weight of 4 KD, was applied. Besides, for target delivery, deoxycholic acid (DCA) as a biologically active compound and a secondary bile acid, capable of interfering with some cancers, were selected. The bile acid was attached to the nanoparticle's surface with a polyethylene glycol (MW = 1 KD) linker via an etherification reaction. Finally, the activity of the prepared compound was studied by means of a clinical CT instrument at various KVp values. The gained results depicted a very high activity of the compound to attenuate X-rays along with making contrast enhancement, even better than those of Visipaque as a commercial contrast agent. In addition, the DCA-PEG-GNPs displayed remarkable stability in a wide range of pHs, i. e. 2.5-11, and in different temperature conditions, ranging between À 78 °C to 48 °C.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.