Background: CT is a diagnostic imaging modality giving higher patient dose in comparison with other radiological procedures, so the calculation of organ dose in CT exams is very important. While methods to calculate the effective dose have been established (ICRP 26 and ICRP 60), they depend heavily on the ability to estimate the dose to radiosensitive organs from the CT procedure. However, dete...

The aim of this study was to investigate and, if possible, compensate for the effect of intravenous contrast-enhanced CT scans on the treatment planning dose distributions for lung patients. The contrast and noncontrast CT scans of 3 patients were registered, and the effect of contrast on the Hounsfield units (HU) was assessed. The effect of contrast was then simulated in the CT scans of 18 pat...

This study was conducted to evaluate the shielding designs of a 6 MeV x-ray linear accelerator scanner used for cargo-container scanning at the port of Tema in Ghana. Workload of the facility had increased significantly over time necessitating review of the installed shielding. There had been introduction of x-ray unit with higher energy (from 5 MeV to 6 MeV) increasing absorbed dose per scan. ...

Background: Medical diagnostic procedures such as X-ray and computed Tomography (CT) scan account for considerable percent of patient's exposure to ionizing radiation. The exposure of cells to Ionization radiation results in induction of DNA damage and chromosomal aberrations. Contrast media (CM) are widely used in diagnostic radiology and CT scan. The aim of this study was to study adverse gen...

Background: Exposure conditions in CT examinations are quite different from conventional Xray. In CT examination higher dose is given to patient in comparison with the dose in other diagnostic examinations. In order to calculate organ effective dose in chest CT, Monte Carlo simulation has been used in this study. Materials and Methods: The Impact survey data were used to determine the ...

abstract   background: the x-ray machines used for radiodiagnosis should meet certain quality assurance (qa) programmes . these are necessary to have good quality radiographs at reasonably low exposure to patients.   materials and methods: dose reduction methods in abdomen x-ray examination were carried out in 10 hospitals in tehran. this paper presents the work, which was implemented on 200 pa...

64/128 slice CT System SCENARIA*, released in 2012, realizes 0.35 s/rot scans not only for cardiac scanning but also for whole body scanning with a high-speed data sampling technique and CORE method (3D reconstruction algorithm) which enables high pitch scans. Furthermore, the image noise reduction technique applied by the iterative reconstruction technology was integrated as a standard functio...

primary and widely in use computed tomography (ct) dose descriptor is a volumetric ct dose index (ctdiv) that is usually measured by a pencil ionization chamber with active length of 100mm and polymethyl methacrylate (pmma) phantom. ctdiv depends on scan parameters such as mas, kv, collimation, tube rotation time but is independent of patient’s size and shape. for the purpose of a good estimati...