• Journal of radiological science and technology
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• v.45 no.4
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• pp.313-320
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• 2022

Both angiography and interventional procedures accompanied by angiography provide many diagnostic and therapeutic benefits to patients and are rapidly increasing. However, unlike general radiography or computed tomography using the same X-ray, the amount of radiation is quite high, but the dose range can vary considerably for each patient and operator. The high sensitivity of the lens to radiation during cerebral angiography and neurointervention is already well known, and although there are many related studies, it is insufficient to easily reduce radiation in diagnosis and treatment. In this situation, in particular, by adding three-dimensional rotational angiography (3D-RA) to the existing two-dimensional (2D) angiography, it is now possible to make an accurate diagnosis. However, since this 3D-RA acquires images through projection of more radiation than before, the exposure dose of the lens may be higher. Therefore, we tried to analyze whether the radiation dose of the lens can be reduced by moving the lens out of the field range by adjusting the table height and magnification ratio during the examination using 3D-RA. The surface dose was measured using a rando phantom and a radiophotoluminescent glass dosimeter (PLD) and the radiation dose was compared by adjusting the table height and magnification ratio based on the central point. As a result, it was found that the radiation dose of the lens decreased as the table height increased from the central point, that is, as the lens was out of the field of view. In conclusion, in 3D-RA, moving the table position of about 2 cm in height will make a significant contribution to the dose reduction of the lens, and it was confirmed that adjusting the magnification ratio can also reduce the surface dose of the lens.

• The Journal of the Korea Contents Association
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• v.11 no.10
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• pp.349-354
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• 2011

The results of the scattery distribution in the fluoroscopy X-ray room were as follows. When the measurement was done at the same height with the table, measured value was 0.78 mGy/min ~ 0.04 mGy/min (95%) within 50 cm and 250 cm. At 50 cm below the table, it was 0.17 mGy/min ~ 0.02mGy/min (86%) and at 50 cm above the table was 1.37 mGy/min ~ 0.05 mGy/min (96%), displaying a decrease. At the same time, the amount of rays were reduced in 50 ~ 60% at the same height with the table than the location 50 cm above the table, 90~95% of reduction rate was observed at 50 cm below the table. For the collimator, comparing to the case when it was completely open, the amount of ray was reduced from 0.78 mGy/min to 0.16 mGy/min at 50cm away and 0.04 mGy/min to 0.01 mGy/min at 250cm away thus approximately 80% on average was reduced when the collimator was reduced to 25%. Comparing with the case when there was a object on the table, the amount of scatter ray was reduced by 96.7% at every location when there is not a object on the table.