Introduction: An operational computed tomography (CT) scanner is a major source of human exposure to ionizing radiation. Exposure increases the risk of cancer and aplastic anaemia. All radiation exposures should be justified and optimized to meet the clinical objective. In order to avoid the administration of excessive radiation dose to patients, diagnostic reference l...

The purpose of these studies was to quantify the effects of radiation given to mouse lungs at intervals up to 6 months after injection of the maximally tolerated dose of cyclophosphamide. In one set of experiments a single i.p. injection of 300 mg/kg of cyclophosphamide was followed at either 1, 3, or 6 months by a range of single doses of gamma-rays delivered to the whole thorax only. In a sec...

background uterine artery embolization (uae) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure. objectives to compare ovarian radiation doses during uterine artery embolization (uae) in patients using conventional digital subtraction angiography (dsa) with those using digital flat-panel technology. patients ...

Health risks of low doses of ionizing radiation (10 cGy or less) may not be accurately estimated in humans by epidemiological study or mathematical modelling because of several inherent confounding factors including environmental, dietary and biological variables that cannot be accounted for in any radio-epidemiological study. In addition, the expression of radiation-induced damage in humans no...

background: radioprotective capability of histamine h2 receptor antagonists have been shown in several in vivo studies mainly using animal models. however, to verify the effectiveness of these agents in clinical applications, studies should be performed on human cells. in the present study radioprotective properties of these agents was examined in vitro on human lymphocytes using metaphase anal...

Current guidelines for limiting exposure of humans to ionizing radiation are based on the linear-no-threshold (LNT) hypothesis for radiation carcinogenesis under which cancer risk increases linearly as the radiation dose increases. With the LNT model even a very small dose could cause cancer and the model is used in establishing guidelines for limiting radiation exposure of humans. A slope chan...

All humans receive some radiation exposure and the risk for radiation-induced cancer at low doses is based on the assumption that there is a linear non-threshold relationship between dose and subsequent effect. Consequently, risk is extrapolated linearly from high radiation doses to very low doses. However, adaptive responses, bystander effects, and death-inducing effect may influence health ef...

BACKGROUND Multidetector computed tomography has been proposed as a tool for routine screening for coronary artery calcification in asymptomatic individuals. As proposed, such screening could involve tens of millions of individuals, but detailed estimates of radiation doses and potential risk of radiation-induced cancer are not currently available. We estimated organ-specific radiation doses an...

OBJECTIVE To investigate radiation doses in pediatric chest radiography in a national survey and to analyze the factors that affect radiation doses. MATERIALS AND METHODS The study was based on the results of 149 chest radiography machines in 135 hospitals nationwide. For each machine, a chest radiograph was obtained by using a phantom representing a 5-year-old child (ATOM® dosimetry phantom,...