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Patient radiation load and possibility of reduction by percutaneous coronary interventions
KVASNICOVÁ, Miroslava
Abstract More than 100 years have passed since physicist W.C.Röntgen discovered X rays and their use in medicine. Knowledge about their harmful effects led to gradual im-plementing of protection rules. Attention of experts gradually focused on persons exa-mined or treated by ionizing radiation, as so-called medical exposition represents the most important part of person´s irradiation from artificial sources of radiation at all. De-finition of medical irradiation was accepted by Act No.18/1997 Coll. (Atomic Act) and extended in novel of the Act (No.13/2002 Coll.). Medical irradiation is not limited but two principles of radiation protection govern {--} principle of reasoning and principle of optimalization. I focused my attention on radiation load of patients during selective coronaro-graphy which still remains gold diagnostic standard for coronary arteries examination. I measured and evaluated the radiation dose of patients at two angiography machines in Teaching Hospital in Motol. They are angiography machines PHILIPS Integris Allura (made in 2002) at Institution of Imaging Methods and PHILIPS Integris HM 3000 (ma-de in 1993) at Cardiovascular Centre for Adults. Some technical parameters of these machines differ, e.g. the size of image amplifier. Since 2003 to 2007 10,087 patients at Cardiovascular Centre for Adults and 7,760 patients at Institution of Imaging Methods were examined by selective coronarography. I analyse all equipment of angiography work place, including technical of X-ray angiomachine, radiological standards, protection against radiation, requirements for imaging system, parameters impacting the quality of X-ray image, possibilities of lowering radiation load in patients. Hypothesis is based on idea that radiation load can be lowered by setting suita-ble exposition parameters and collimators. Methodology consists of measurements of exposition dose in 100 patients at Institution of Imaging Methods and at Cardivascular Centre. I compare the dose at both work places on the base of different size of image amplifier, different frequency of scanning and advert to different dose in different projection. Other part consists of mea-surements on phantoms, in which I compare the dose acquired in patients. I watch fur-ther parameters impacting the level of radiation load. Acquired results are mutually compared and statistically elaborated and valuated by {$\omega$}2-test. Evaluated data can serve for creating of radiologic standards which will contribute to staff education how to ma-nipulate sources of X-ray radiation to make the dose for a patient and for staff as low as possible.
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