conclusion by comparing the results, we saw that w/rh anode/filter combination is the best choice in breast mammography imaging because of the lowest delivered dose in comparison with w/ag and rh/al. moreover, breast thickness and g value have significant effects on mgd. objectives the aim of this study was to determine the average absorbed dose of x-ray radiation in the glandular tissue of the...

introduction: poor sensitivity and poor signal to noise ratio because of low injected thallium dose and presence of scattered photons are the main problems in using thallium in scintigraphic imaging of the heart. scattered photons are the main cause of degrading the contrast and resolution in spect imaging that result in error in quantification. thallium decay is very complicated and photons ar...

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: gamma knife is an instrument specially designed for treating brain disorders. in gamma knife, there are 201 narrow beams of cobalt-60 sources that intersect at an isocenter point to treat brain tumors. the tumor is placed at the isocenter and is treated by the emitted gamma rays. therefore, there is a high dose at this point and a low dose is delivered to the normal tissue surroun...

OBJECTIVE To compare between the American College of Radiology (ACR) accreditation phantom and digital mammography accreditation phantom in assessing the image quality in full-field digital mammography (FFDM). MATERIALS AND METHODS In each week throughout the 42-week study, we obtained phantom images using both the ACR accreditation phantom and the digital mammography accreditation phantom, a...

PURPOSE To develop a realistic yet flexible 4D digital phantom based on patient anatomy for dynamic estimation of organ doses due to external ionizing radiation. METHODS In this work, we propose to build a 4D digital phantom based on patient CT anatomy and time-tagged CT information. A regional 4D-CT is first acquired on the patient around lesion with a RPM system. By binning CT information a...

Currently daily quality control (QC) tests for mammography systems are generally evaluated by using visual analysis phantoms, which of course means subjective measurement. In our study, however, we evaluated a novel digital phantom, the 1Shot Phantom M plus (1Shot Phantom), together with automatic analysis software dedicated for mammography systems using Fuji computed radiography (FCR). The dig...

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...

We investigated the appropriateness of four different mammography phantoms for image quality evaluation in Digital Breast Tomosynthesis (DBT). We tested the CIRS BR3D phantom, the ACR Prototype FFDM Accreditation Phantom, the Penn anthropomorphic breast phantom and the Quart mam/digi EPQC phantom. This work discusses the advantages and shortcomings of each phantom and concludes that none of the...

RATIONALE AND OBJECTIVES To examine the effectiveness and suitability of a quality control (QC) phantom for a routine QC program in digital radiography. MATERIALS AND METHODS The chest phantom consists of copper and aluminum cutouts arranged to resemble the appearance of a chest. Performance of the digital radiography (DR) system is evaluated using high and low contrast resolution objects pla...