Program Information
A Program for Fetal and Peak Skin Dose Estimations for Radiographic and Fluoroscopic Examinations
V Garcia*, W Wang , University of Oklahoma Health Science Center, Oklahoma City, OK
Presentations
MO-RAM-GePD-IT-5 (Monday, July 31, 2017) 9:30 AM - 10:00 AM Room: Imaging ePoster Theater
Purpose: Exposure of the fetus to radiation presents potential risks and hazards to fetal growth and development. It is necessary to create a program to estimate the dose to conceptus for various diagnostic exams for individual radiographic and fluoroscopic units. Prolonged fluoroscopy at high doses can cause skin injury and epilation. Therefore, skin dose estimation is accounted for in the program.
Methods: Calculations are done using the Percent Depth Dose (PDD) method. As per PDD, the quantities needed from the diagnostic exam are peak kilovoltage (kVp), milliampere-seconds (mAs), patient thickness, fetal depth, X-ray field size at the image receptor, and, in the case of fluoroscopy, the exposure rate at the image receptor and time. Using the annual survey reports, the half-value layer (HVL) and exposure per mAs (mR/mAs) can be determined. Field size and exposure at the entrance of the X-rays can be calculated. Using previous calculations and data, percent of dose at fetal depth can be found. Peak skin dose from fluoroscopy procedures is determined by using displayed accumulated air kerma, backscatter factor, table height, and table attenuation.
Results: The program calculates fetal dose as functions of kVp, mAs, patient thickness, fetal depth, and field size. The annual survey reports were imported into Excel to allow for the dose to be calculated on an individual unit basis. For radiographic exams, calculations account for both lateral and anterior-posterior (AP) exposures to the patient. The program can also calculate interventional radiology peak skin dose for AP, lateral, and rotational digital angiography.
Conclusion: Radiation risk is considered negligible under 50 mGy and significantly increased above 150 mGy for the fetus. Using the calculations, risk from fetal exposure to radiation can accurately be assessed for patients. Peak skin dose estimation can be used to assess the possibility of skin damage.
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