Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 13 of 13 for “"scatter correction"”.
-
Comparative assessment of several SPECT scatter correction methods using SimSPECT
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 1997.
-
X-ray CT scatter correction by a physics-motivated deep neural network
… problem in X-ray Computed Tomography (CT) is the scatter occurring due to the interaction of photons with the imaged object. Unless it is corrected, this phenomenon manifests itself as degradations in the reconstructions in the form of various artifacts. This makes scatter correction a critical …
-
Optimizing Kilovoltage Cone-Beam Computed Tomography for Image-Guided Radiation Therapy
… Hounsfield Units as a result of in-patient scatter. The specific aims of this dissertation research are to: 1) reduce noise associated with the low-dose CBCT scans acquired with low tube current/time (mAs) protocols by the application of innovative software; and 2) develop a moving blocker …
-
Improving attenuation corrections obtained using singles-mode transmission data in small-animal PET
… within the subject being imaged. These corrections can be obtained using singles-mode photon transmission scanning. Although suitable for small animal PET, these scans are subject to high amounts of contamination from scattered photons. Currently, no accurate correction exists to account …
-
A Scheme for Ultra-Fast Computed Tomography Based on Stationary Multi-Beam X-ray Sources
… interior CT: interior CT mode, X-ray scattering, and scatter correction methods. First, a single CNT X-ray source based interior micro-CT was constructed to serve as a down-scaled experimental verification platform for interior CT mode. Interior CT mode demonstrated comparable …
-
X-ray Scatter Computation and Simulation in Cone Beam Computed Tomography
… signal can be contaminated by a large amount of scattered photons due to x-ray interactions with the irradiated object. The photon scatter can severely degrade the quality of the reconstructed CT images by creating artifacts and quantification errors. Thus scatter correction has become an …
-
An experimental and theoretical approach to correct for the scattered radiation in an X-ray computer tomography system for industrial applications
… 450 kV X-ray tubes is the high amount of scattered radiation which is added to the primary radiation (signal). This stray radiation leads to a significant degradation of the image quality. A better understanding of the scattering and methods to reduce its effects are therefore necessary to …
-
Characterization of a 6 MV photon beam in terms of primary and scattered dose components
… SL75-5 linear accelerator into primary and scattered dose components in water. The two quantities that are necessary to define the primary beam component are a reference dose DR and a primary linear attenuation coefficient μ 0. DR describes the magnitude of the primary dose as a …
-
The development and application of online modelling methods
… for variations due to specular and diffuse scattering effects, extended multiplicative scatter correction was applied to the data. As with the polymer study, DOE was used to determine the best method of data pre-processing prior to the partial least squares modelling. The best method of …
-
Developing a spectroscopy-based high throughput assay for anthocyanin content in corn
… pretreated with a combination of multiplicative scatter correction (MSC) and second order Savitzky-Golay (SG) derivative. The scores plot of the model showed a prominent separation between red and yellow corn blends as compared to other models. With RPD = 1.6 and RER = 4.7, the model was useful …
-
An investigation into the limitations of myocardial perfusion imaging
… clinical interpretation.<br/><br/>Attenuation correction procedures using transmission sources, have been available for some time, but have not been adopted widely, amidst concern that they introduce additional artefacts. This study determined the effectiveness of these methods by establishing …
-
Investigating aquaphotomics for fruit quality assessment
… in the second overtone region of water. Two correction pre-treatments; extended multiplicative scatter correction (EMSC) and external parameter orthogonalization (EPO) were used in conjunction with principal component loading of water as an interferent spectrum. They were able to correct for …
-
Reconstruction Algorithms for Novel Joint Imaging Techniques in PET
… data may be compensated through attenuation and scatter correction in image reconstruction. However, a potential solution is to place the insert outside of the scanner's axial FOV and to move the body to be in proximity of the insert. We call this imaging strategy the <i>surveillance</i> mode. As …