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We present an analytical method to compute the basis image noise in the context of multi-energy x-ray imaging based on the Cramér-Rao lower bound (CRLB). The proposed formalism extends the original idea of Alvarez and Macovski (1976 Phys. Med. Biol. 21 733) to estimate the noise in the photo-effect and Compton-effect basis images in the case of dual-energy(More)
PURPOSE To investigate the potential of spectral computed tomography (CT) (popularly referred to as multicolor CT), used in combination with a gold high-density lipoprotein nanoparticle contrast agent (Au-HDL), for characterization of macrophage burden, calcification, and stenosis of atherosclerotic plaques. MATERIALS AND METHODS The local animal care(More)
Theoretical considerations predicted the feasibility of K-edge x-ray computed tomography (CT) imaging using energy discriminating detectors with more than two energy bins. This technique enables material-specific imaging in CT, which in combination with high-Z element based contrast agents, opens up possibilities for new medical applications. In this paper,(More)
The purpose of this study was to investigate whether spectral computed tomography (CT) has the potential to improve luminal depiction by differentiating among intravascular gadolinium-based contrast agent, calcified plaque, and stent material by using the characteristic k edge of gadolinium. A preclinical spectral CT scanner with a photon-counting detector(More)
After passage through matter, the energy spectrum of a polychromatic beam of x-rays contains valuable information about the elemental composition of the absorber. Conventional x-ray systems or x-ray computed tomography (CT) systems, equipped with scintillator detectors operated in the integrating mode, are largely insensitive to this type of spectral(More)
PURPOSE To evaluate the capability of spectral computed tomography (CT) to improve the characterization of cystic high-attenuation lesions in a renal phantom and to test the hypothesis that spectral CT will improve the differentiation of cystic renal lesions with high protein content and those that have undergone hemorrhage or malignant contrast-enhancing(More)
OBJECTIVES Phase-contrast and scattering-based x-ray imaging are known to provide additional and complementary information to conventional, absorption-based methods, and therefore have the potential to play a crucial role in medical diagnostics. We report on the first mammographic investigation of 5 native, that is, freshly dissected, breasts carried out(More)
PURPOSE Gold nanoparticles (gold-NPs) have lately been proposed as alternative contrast agents to iodine-based contrast agents (iodine-CA) for computed tomography (CT) angiography. The aims of this study were to confirm an appropriate environment in which to evaluate such novel contrast agents, to investigate the comparative contrast of iodine-CA versus(More)
PURPOSE The purpose of this work is to combine two areas of active research in tomographic x-ray imaging. The first one is the use of iterative reconstruction (IR) techniques. The second one is differential phase contrast imaging (DPCI). METHODS The authors derive a maximum likelihood (ML) reconstruction algorithm with regularization for DPCI. Forward and(More)
We report a novel molecular imaging agent based on ytterbium designed for use with spectral "multicolor" computed tomography (CT). Spectral CT or multicolored CT provides all of the benefits of traditional CT, such as rapid tomographic X-ray imaging, but in addition, it simultaneously discriminates metal-rich contrast agents based on the element's unique(More)