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Imaging phantom

About: Imaging phantom is a research topic. Over the lifetime, 28170 publications have been published within this topic receiving 510003 citations. The topic is also known as: phantom.


Papers
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Journal ArticleDOI
TL;DR: A method for reconstructing vessel surfaces from 3-D angiographic methods that allows for objective measurement of vessel stenosis and is a deformable model that employs a tubular coordinate system.
Abstract: Three-dimensional (3-D) angiographic methods are gaining acceptance for evaluation of atherosclerotic disease. However, measurement of vessel stenosis from 3-D angiographic methods can be problematic due to limited image resolution and contrast. We present a method for reconstructing vessel surfaces from 3-D angiographic methods that allows for objective measurement of vessel stenosis. The method is a deformable model that employs a tubular coordinate system. Vertex merging is incorporated into the coordinate system to maintain even vertex spacing and to avoid problems of self-intersection of the surface. The deformable model was evaluated on clinical magnetic resonance (MR) images of the carotid (n=6) and renal (n=2) arteries, on an MR image of a physical vascular phantom and on a digital vascular phantom. Only one gross error occurred for all clinical images. All reconstructed surfaces had a realistic, smooth appearance. For all segments of the physical vascular phantom, vessel radii from the surface reconstruction had an error of less than 0.2 of the average voxel dimension. Variability of manual initialization of the deformable model had negligible effect on the measurement of the degree of stenosis of the digital vascular phantom.

186 citations

Journal ArticleDOI
TL;DR: In this article, a combined local and global optical flow algorithm is proposed to correct motion artifacts in positron emission tomography (PET) images for 3D volume sets, which is based on the combined Local and Global Optical Flow algorithm with modifications to allow for discontinuity preservation across organ boundaries.
Abstract: The problem of motion is well known in positron emission tomography (PET) studies. The PET images are formed over an elongated period of time. As the patients cannot hold breath during the PET acquisition, spatial blurring and motion artifacts are the natural result. These may lead to wrong quantification of the radioactive uptake. We present a solution to this problem by respiratory-gating the PET data and correcting the PET images for motion with optical flow algorithms. The algorithm is based on the combined local and global optical flow algorithm with modifications to allow for discontinuity preservation across organ boundaries and for application to 3-D volume sets. The superiority of the algorithm over previous work is demonstrated on software phantom and real patient data.

186 citations

Journal ArticleDOI
TL;DR: The results support the use of training with virtual feedback to alleviate phantom limb pain and suggest between-participant differences in the effectiveness of the treatment might be related more to a difference in the susceptibility to the virtual visual feedback, than to factors related to the lesion, such as the duration of the deafferentation.
Abstract: Background. Performing phantom movements with visual virtual feedback, or mirror therapy, is a promising treatment avenue to alleviate phantom limb pain. However the effectiveness of this approach ...

186 citations

Journal ArticleDOI
TL;DR: The objective of this paper is the reduction of inter-scanner differences in the FDG-PET scans obtained from the 50 participating PET centers having fifteen different scanner models.

186 citations

Journal ArticleDOI
TL;DR: An improved phantom material for use in near-infrared spectroscopy and imaging consisting of a clear epoxy resin with absorbing dyes and amorphous silica spheres as scattering particles shows good agreement between prediction and experimental measurements.
Abstract: In this note, we describe an improved phantom material for use in near-infrared spectroscopy and imaging. The material consists of a clear epoxy resin with absorbing dyes and amorphous silica spheres as scattering particles. It is possible to calculate the scattering coefficient and angular scattering distribution of the material from Mie theory, using the known size and refractive index of the silica spheres together with the measured refractive index of the resin (approximately 1.56). We show a good agreement between prediction and experimental measurements. The scattering properties of the material closely match those of tissue in the near-infrared wavelength region, having an anisotropy factor, g, of approximately 0.93. The absorption coefficient of the epoxy is low (approximately 0.001 mm-1), and addition of the dyes produces an absorption coefficient that covers the same range as that of tissue.

185 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,623
20223,476
20211,221
20201,482
20191,568
20181,503