BACKGROUND Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. OBJECTIVE This study is aimed at evaluating radiation dose to patients from ...

The purpose of bowtie filters in CT scanners is to homogenize the x-ray intensity measured by the detectors in order to improve the image quality and at the same time to reduce the dose to the patient because of the preferential filtering near the periphery of the fan beam. For CT dosimetry, especially for Monte Carlo calculations of organ and tissue absorbed doses to patients, it is important ...

Mobile fluoroscopy (c-arm) units offering 3D image reconstruction are becoming more common in surgical settings. Although these images are "CT-like" and sometimes replace the postoperative CT, the acquisition is technically very different from a traditional CT acquisition. Dose assessment is complicated by a large beam width, automatic exposure rate control, and a rotation of less than 360°. Th...

We present an experimental validation of a kilovoltage (kV) X-ray source characterization model in an anthropomorphic phantom to estimate patient-specific absorbed dose from kV cone-beam computed tomography (CBCT) imaging procedures and compare these doses to nominal weighted CT-dose index (CTDIw) dose estimates. We simulated the default Varian on-board imager 1.4 (OBI) default CBCT imaging pro...

This report summarises work undertaken in support of a European Commission (EC) Concerted Action on CT that has included both a review and further development of the framework for CT dosimetry. The system previously established by the EC for reference doses in CT (with the quantities weighted CTDI (CTDIw) and dose-length product (DLP)) has been expanded to include subsequent developments in CT ...

BACKGROUND AND PURPOSE Optimal tube voltage and tube current settings are not well established. The purpose of our study was to investigate the image quality on 3D CT angiograms of the brain at various kilovoltage settings by evaluating the depiction of simulated intracranial lesions by using a vascular phantom. MATERIALS AND METHODS An anthropomorphic vascular phantom with superimposed bone ...

abstract   background: while the benefits of computed tomography (ct) are well known in accurate diagnosis, those benefits are not risk free. ct is a device with higher patient dose in comparison with other conventional radiological procedures. is the reduction of exposures by requiring optimization of ct procedures [a principle concern in radiological protection]? in this study, the radiation ...

A pelvimetry examination is sometimes prescribed to a pregnant woman at the end of her pregnancy in order assess dimensions pelvis prior childbirth. This has long been performed by using X-ray, but now increasingly being replaced CT-scan The objective this study radiation doses received during practical CT Hitashi Supria 16-slice scanner. were estimated Monte Carlo (MC)-based simulation with GA...