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(s): the aim of this study was to determine the optimal reconstruction parameters for iterative reconstruction in different devices and collimators for dopamine transporter (dat) single-photon emission computed tomography (spect). the results were compared between filtered back projection (fbp) and different attenuation correction (ac) methods.methods: an anthropomorphic striatal phant...

in present pet/ct scanners, pet attenuation correction is performed by relying on the information given by ct scan. in the ct-based attenuation correction methods, dual-energy technique (dect) is the most accurate approach, which has been limited due to the increasing patient dose. in this feasibility study, we have introduced a new method that can implement dual-energy technique with only a si...

Natural attenuation of the environmental contaminant perchlorate is a cost-effective alternative to current removal methods. The success of natural perchlorate remediation is dependent on the presence and activity of dissimilatory (per)chlorate-reducing bacteria (DPRB) within a target site. To detect DPRB in the environment, two degenerate primer sets targeting the chlorite dismutase (cld) gene...

Background: In this study, Quantitative 32P bremsstrahlung planar and SPECT imaging and consequent dose assessment were carried out as a comprehensive phantom study to define an appropriate method for accurate Dosimetry in clinical practice. Materials and Methods: CT, planar and SPECT bremsstrahlung images of Jaszczak phantom containing a known activity of 32P were acquired. In addition, Phanto...

Background: Lead glass has a wide variety of applications in radiation protection. This study aims to investigate some characteristics of lead glass such as the γ-ray energy-dependent mass and linear attenuation coefficients, the half-value layer thickness, and the absorbed dose distribution for specific energy. Materials and Methods: The attenuation parameters of different lead glass types aga...

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...

The Arenaviridae family includes several hemorrhagic fever viruses which are important emerging pathogens. Junín virus, a member of this family, is the etiological agent of Argentine Hemorrhagic Fever (AHF). A collaboration between the Governments of Argentina and the USA rendered the attenuated Junín virus vaccine strain Candid#1. Arenaviruses are enveloped viruses with genomes consisting of t...

Ultramafic rocks of the ophiolitic complexes are prone to alteration and degradation, and therefore, ease of mobility of heavy metals such as nickel (Ni), chromium (Cr), cobalt (Co), lead (Pb), and vanadium (V), resulting in environmental hazards. The ultramafic rocks of the ophiolitic realm of Kurdistan province, west of Iran, show field and compositional evidence for such hazardous conditions...