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...

Improvements in image quality and quantitation measurement, and the addition of detailed anatomical structures are important topics for single-photon emission tomography (SPECT). The goal of this study was to develop a practical system enabling both nonuniform attenuation correction and image fusion of SPECT images by means of high-performance X-ray computed tomography (CT). A SPECT system and ...

UNLABELLED A poor signal-to-noise ratio attributable to a low injected dose of thallium and the presence of scattered photons are the major impediments in the use of thallium as an imaging agent. Thallium decays in a complicated way and emits photons in a wide range of energies (68-82 keV). To increase the ratios of primary photons to scatter photons (primary-to-scatter ratios) and possibly inc...

BACKGROUND Developments in single photon emission tomography instrumentation and reconstruction methods present a potential for decreasing acquisition times. One of such recent options for myocardial perfusion imaging (MPI) is IQ-SPECT. This study was motivated by the inconsistency in the reported ejection fraction (EF) and left ventricular (LV) volume results between IQ-SPECT and more conventi...

We have developed an approach to detect and co"ect patient motion that occurs during SPECT imaging. The detection of patient motion is based on frame-to-frame matching, using phase-only matched .filtering (POMF). The co"ection procedure has been designed to co"ect any translational patient motion and alert the operator to other kinds of patient movement. The precision in co"ecting translational...

objective: the aim of this study was to evaluate the influences of reconstruction and attenuation correction on the differences in the radioactivity distributions in 123i brain spect obtained by the hybrid spect/ct device. methods: we used the 3-dimensional (3d) brain phantom, which imitates the precise structure of gray mater, white matter and bone regions. it was filled with 123i solution (20...

Introduction: In this study the evaluation of a Platelet-based Maximum Penalized Likelihood Estimation (MPLE) for denoising SPECT images was performed and compared with other denoising methods such as Wavelets or Butterworth filtration. Platelet-based MPLE factorization as a multiscale decomposition approach has been already proposed for better edges and surfaces representation due to Poisson n...

Introduction: One of the main steps in the optimization process in diagnostic imaging is the quality control of radiology devices. The usual method of CT scan calibration is used of a phantom. The phantom created a certain weakening for the radiation through which it passes. One of the most suitable methods for quantitative analysis of the resolution and contrast in CT scan im...

Objective(s): Systemic lupus erythematosus (SLE) is an autoimmune disease with a wide range of clinical manifestations. Cognitive dysfunction is one of the manifestations that could present prior to the emergence of any other neuropsychiatric involvements in SLE. Cognitive dysfunction is a subtle condition occurring with ahigh frequency. However, there is no data on the correlation of cognitive...

Quantitative SPECT imaging of In is of growing importance in nuclear medicine applications like patient-specific radionuclide dosimetry. In this study, the quality of a Monte-Carlo based model of the imaging chain from nuclear decay to detection in a gamma camera is investigated. Important characteristics like the camera point spread function (PSF), the phantom attenuation and scatter effects a...