Abbreviations 2D, 3D 2-dimensional, 3-dimensional CZT cadmium zinc telluride EKG electric signal from the heart FBP filtered backprojection FOV field-of-view GE General Electric Ge(Li) germanium detector doped with lithium MLEM maximum likelihood expectation maximization NaI(Tl) sodium iodine doped with thallium NM nuclear medicine OSEM ordered subset expectation maximization PET positron emiss...

Introduction: Scattered photon is one of the main defects that degrade the quality and quantitative accuracy of nuclear medicine images. Accurate estimation of scatter in projection data of SPECT is computationally extremely demanding for activity distribution in uniform and non-uniform dense media. Methods: The objective of this paper is to develop and validate a scatter correction technique ...

MEDISIP Medical Imaging and Signal Processing Group, Ghent University, IBBT-IBiTech, iMinds Medical IT, Ghent, Belgium In Time-of-Flight PET/MRI systems accurate attenuation correction, based on the MRI image, is not straight forward. An alternative is attenuation correction based on emission data only. This is for instance done by simultaneous reconstruction of attenuation and activity with th...

PURPOSE Presence of photon attenuation severely challenges quantitative accuracy in single-photon emission computed tomography (SPECT) imaging. Subsequently, various attenuation correction methods have been developed to compensate for this degradation. The present study aims to implement an attenuation correction method and then to evaluate quantification accuracy of attenuation correction in s...

The nuclides inhaled during nuclear accidents usually cause internal contamination of the lungs with low activity. Although a parallel-hole imaging system, which is widely used in medical gamma cameras, has high resolution and good image quality, owing to its extremely detection efficiency, it remains difficult obtain images lung contamination. In this study, Monte Carlo method was study using ...

UNLABELLED Iterative reconstruction has become the standard for routine clinical PET imaging. However, iterative reconstruction is computationally expensive, especially for time-of-flight (TOF) data. Block-iterative algorithms such as ordered-subsets expectation maximization (OSEM) are commonly used to accelerate the reconstruction. There is a tradeoff between the number of subsets and reconstr...

The main goal of SPECT imaging is to determine the distribution of injected activity inside patient’s body. However, due to photon attenuation, a quantitative study is encountered with remarkable error. Using Monte Carlo method, it is possible to find the most precise relationship between activity distribution and its projections. Therefore, it is impossible to create mathematical projections t...

Parallel projection based Single Photon Emission Computed Tomography (SPECT) is one of the most widely used nuclear imaging technique even nowadays. Serious artefacts are produced in the reconstructed images due to the non-homogeneous attenuation medium and the distance dependent spatial resolution (DDSR) of the parallel imaging. Effective non-uniform attenuation correction and DDSR reduction p...