Introduction: In X-ray diagnostic we use ionising radiation which can have harmful effects on the person’s health who was exposed to the radiation. For the exposure to be reduced to a certain degree, the X-ray machine alone already has built-in components, that reduce the dose for the patient in its own way. Purpose: We wanted to research the effect of the added filtration and tube voltage on DAP, the effective dose and the dose for the organs that the patient receives. Methods: We x-rayed the lumbar spine in AP and lateral projection. At first, we did the acquisition with just the inherent tube filtration and then the copper filters of different thickness where added. We measured the dose area product (DAP). At last, we calculated the effective dose and the dose of the organs which we did with the PCXMC 2.0 programme, that uses the Monte Carlo simulation. The purpose of this part of the diploma work was to test if any deviation is present between DAP, the effective dose and the dose that the organs receive. Results: With the information from the HVL measurements we acknowledged that when the filtration is added, the HVL increases. Based on the data that we acquired we found out that when the tube voltage is raised, DAP also raises. We discovered that when we increased the copper filtration, DAP decreases. From the data we noticed that when the thickness of filtration is added the effective dose and the dose on the organs increases. When the information from the doses for the organs was processed, we found out that the dose increased the most for the colon in both projections, the ovaries in the AP projection, the testicles in the lateral projection, and the thymus in both projections but the thymus receives a small amount of the dose, so the high increase isn’t problematic. The only organ where the dose decreased was the skin in both projections. While we calculated the contribution of the organs to the effective dose, we discovered, that most of the dose contributes the stomach, colon, urinary bladder and the gonads in the AP projection. In the lateral projection the most of the effective dose contributes the stomach, colon, bone marrow and the gonads. Discussion and conclusion: It was proven that when the thickness of the added filtration is increased DAP decreases, but the dose on the organs actually increases. Based on the acquired data with this diploma work we recommend the use of added filtration with even greater consideration and substantiate than it is at the moment, with the regard on the dose that the patient receives.
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