The purpose of this paper is to briefly explain report 160 of the National Council on Radiation Protection and Measurement and the significance of the report to medical imaging as a whole and nuclear medicine specifically. The implications of the findings of report 160 have had repercussions and will continue to affect all of ionizing radiation medical imaging. The nuclear medicine community sh...

BACKGROUND General practitioners (GPs) often decide to refer patients for medical imaging with ionizing radiation and are therefore responsible for assessing the benefits of the procedure against the possible risks. OBJECTIVE To assess the level of general practitioners' knowledge concerning radiation doses for patients undergoing common radiological investigations and the associated risks of...

QUESTION One of my patients had a computed tomography scan of her abdomen a week ago and has just found out she is 7 weeks pregnant. What should I tell her about the pregnancy and the risk to her fetus? ANSWER Your patient is not at increased risk of miscarriage or major congenital fetal malformations due to radiation exposure. Her risk is similar to that of the general population (ie, 1% to ...

1.1 Ionizing radiation Human exposure to ionizing radiation is a natural part of life on earth. These exposures occur every day from radiation associated with naturally occurring radionuclides in soil, air, and food, and also from cosmic rays. In addition, many people are exposed to dental and medical diagnostic procedures and therapy involving: x rays, gamma rays, charged particles, radionucli...

Recent preclinical studies have suggested that radiotherapy in combination with antiangiogenic/vasculature targeting agents enhances the therapeutic ratio of ionizing radiation alone. Because radiotherapy is one of the most widely used treatments for cancer, it is important to understand how best to use these two modalities to aid in the design of rational patient protocols. The mechanisms of i...

There is little known about the regulation of gene expression by ionizing radiation exposure. The present studies demonstrate transcriptional activation of a mammalian gene, the c-jun protooncogene, by x-rays. The c-jun gene encodes a component of the AP-1 protein complex and is important in early signaling events involved in various cellular functions. The increase in c-jun transcripts by ioni...

Both ionizing radiation and docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid (PUFA), have been shown to inhibit tumor cell growth at least in part by increasing oxidative stress. In this study, the effects of ionizing radiation, DHA, or a combination of the two on cell proliferation, anchorage-independent growth, apoptosis, and lipid peroxidation in A549 lung adenocarcinoma cells w...

The decomposition of Cistus incanus leaf litter, a summer deciduous species, was compared to that of Myrtus communis, an evergreen species, during 15 months of incubation in a Mediterranean low shrubland. The litterbags were placed under randomly selected shrubs of Myrtus and Cistus, respectively. Owing to the different microclimatic conditions under deciduous and evergreen shrubs Cistus litter...

When ionizing radiation passes through a material it imparts some of its energy to that material. The imparted energy may be high enough to cause a break in bonds inside the molecules or between molecules or both, in such cases, free radicals are created. The type, lifetime, extent, fate and origin of those free radicals may differ according to several factors; most of them are beyond the subje...