نتایج جستجو برای: spect reconstruction
تعداد نتایج: 133449 فیلتر نتایج به سال:
SPECT has traditionally been regarded as nonquantitative. Advances in multimodality γ-cameras (SPECT/CT), algorithms for image reconstruction, and sophisticated compensation techniques to correct for photon attenuation and scattering have, however, now made quantitative SPECT viable in a manner similar to quantitative PET (i.e., kBq cm(-3), standardized uptake value). This review examines the e...
background: photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of spect images and results to errors in accuracy of quantitative measurements. this can be corrected via different physical or mathematical approaches. as the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘piece wise line...
Introduction: Gated SPECT myocardial perfusion scanning has new capabilities in addition to its main applications such as left ventricular dyssynchrony using phase analysis. Phase analysis has been investigated through various software including Emory Cardiac Toolbox (ECTb) and Quantitative Gated SPECT (QGS). The aim of this study is to evaluate the effect of reconstruction par...
Purpose. Striatal single photon emission computed tomography (SPECT) imaging of the dopaminergic system is becoming increasingly used for clinical and research studies. The question about the value of nonuniform attenuation correction has become more relevant with the increasing availability of hybrid SPECT-CT scanners. In this study, the value of nonuniform attenuation correction and correctio...
In order to model photon attenuation and detector resolution variation as a depth-dependent convolution for efficient reconstruction of quantitative SPECT, a central-ray approximation is necessary. This work investigates the impact of the approximation upon reconstruction accuracy and computational efficiency. A patient chest CT image was acquired and converted into an object-specific attenuati...
A new imaging principle for object reconstruction is proposed in Single Photon Emission Computer Tomography (SPECT) which is widely used in nuclear medicine. The quality of SPECT images is largely affected by many adverse factors among which chiefly Compton scattering of gamma rays. Recently we have proposed to exploit Compton scattered radiation to generate new data necessary for object recons...
Nuclear cardiac imaging is a noninvasive, sensitive method providing information on cardiac structure and physiology. Single photon emission tomography (SPECT) evaluates myocardial perfusion, viability, and function and is widely used in clinical routine. The quality of the tomographic image is a key for accurate diagnosis. Image filtering, a mathematical processing, compensates for loss of det...
BACKGROUND: This study focuses on quantitative reconstruction of dynamic cardiac SPECT. MATERIAL AND METHODS: The Karhunen-Loeve (KL) transform is first applied to gated frames or sinogram data to de-correlate the dynamic information along the time direction. Then the Poisson noise is treated by a penalized weighted least-squares minimization, followed by an analytical inversion of the treated...
Background: Photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of SPECT images and results to errors in accuracy of quantitative measurements. This can be corrected via different physical or mathematical approaches. As the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘Piece ...
OBJECTIVE The aim of the study was to determine the influence and clinical consequences of different tomographic reconstruction algorithms on the image quality and diagnostic accuracy of low count statistics single photon emission computed tomography (SPECT). METHODS Phantom scans were used to assess the image quality (percentage of recovered contrast, relative noise level, and spatial resolu...
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