background: the radiation doses resulting from diagnostic x-ray examinations are routinely measured in terms of entrance surface dose (esd) and effective dose (ed). in this study, for the purpose of radiation protection, the radiation doses received from digital chest x-ray examination were evaluated in terms of esd and ed. material and methods: the ed was calculated by using the mcnp monte car...

Background: The Diagnostic reference levels (DRLs) play a critical role in the optimization of radiation dose especially, in some conditions like pediatrics. They are useful indicators by which the radiologists can be aware of delivered excess radiation doses to the patients, and take corrective actions if necessary. In order to meet some requirements for establishing the national computed tomo...

Introduction: International Commission on Radiological Protection introduced three basic principles of radiation protection, namely justification, optimization, and dose limit. Medical exposure has no dose limits, and generally, diagnostic reference levels are used as a tool for optimization of patient protection. Material and Methods: Dosimetry was performed on 20 CT scanners located in 14 cit...

Background: In diagnostic radiology there are two reasons for measuring or estimating radiation doses to patients. Firstly measurements provide a means for setting and checking standards of good practice as an aid to the optimization of patient protection. Secondly estimates of the absorbed dose to tissue and organs in the patients. Materials and Methods: A total of 2382 patients were studied t...

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 ...

Before a new test is introduced in clinical practice, its accuracy should be assessed. In the past decade, researchers have put an increased emphasis on exploring differences in test sensitivity and specificity between patient subgroups. If the reference standard is imperfect and the prevalence of the target condition differs among subgroups, apparent differences in test sensitivity and specifi...

introduction: based on the existing studies, measuring serum level of immunoglobulin for making decisions regarding prescription of tetanus prophylaxis seems logical and cost effective. therefore, the present study was done with the aim of evaluating the diagnostic accuracy of tetanus quick stick (tqs) in comparison with elisa method in this regard. methods: the present diagnostic accuracy stud...

We describe a general solution to the problem of determining diagnostic accuracy without the use of a perfect reference standard and in the presence of interpreter variability. The accuracy of a diagnostic test is typically determined by comparing its outcomes with those of an established reference standard. But the accuracy of the standard itself and those of the interpreters strongly influenc...