The main estimator of the risk of radioinduced carcinogenesis in digital mammography is the mean glandular dose (MGD), which is evaluated in phantom during periodic quality controls of the equipment, being necessary for this purpose to obtain output and half value layer (HVL) values in the range of the kVp used clinically. Robson's parametric method makes it possible to obtain all the outputs and HVLs required for the determination of the DGM in a mammographic device from the measurement of output and HVL for a...

The study was performed on a Hologic 3Dimensions digital mammograph. The exposures were taken in "Zero Degree" mode (with all projections at 0°), measured with a Black Piranha RTI and Ocean 2014 software, for the whole kVp range available in the anode-filter combinations W/0.7 mm Al and W/50 µm Ag. Measurements have been corrected for focus-detector distance and Dance factor.

For Output=A(kV)n fit the values obtained are A=0.0169, n=2.1441 and R2=0.9903 for W/Ag and A=0.0057, n=2.5992 and R2=0.9947 for W/Al. For Output=a1∙kV2+a2∙kV+a3 fit the values obtained are a1=-0.0498, a2=4.9838, a3=-79.463 and R2=0.9997 for W/Ag and a1=0.0309, a2=1.8841, a3=-44.058 and R2= 0.9981 for W/Al. For HVL=a∙kV2+b∙kV+c fit the values obtained are a=-0.001, b=0.0751, c=-0.7707 and R2=0.9908 for W/Ag and a=-0.0003, b=0.0375, c=-0.3446 and R2=0.999 for W/Al.

The average difference found between the HVL calculation with the proposed setting and the measured values is 0.017 mm Al for the W/Ag anode-filter combination and 0.006 mm Al for the W/Al anode-filter combination, being lower than 0.025 mm Al and lower than 0.01 mm Al for W/Ag and W/Al respectively for all kVp values used. The average deviations found between the output calculation with the proposed settings and the measured values are 3.92% and 1.72% for the potential and polynomial settings respectively. The average...

1. Robson K J. A parametric method for determining mammographic X-ray tube output and half value layer, The British Journal of Radiology. 2001; 74: 335-340. 2. Solís Preciado N et al. Propuesta de un nuevo ajuste para el cálculo del rendimiento y análisis de su influencia en la estimación de la dosis glandular, Rev Fis Med. 2020; 21(1): 19-31.

S. HONORATO HERNANDEZ: Nothing to disclose P. Garcia Castañon: Nothing to disclose R. Rosado del Castillo: Nothing to disclose G. Paradela Díaz: Nothing to disclose C. PRIETO MARTIN: Nothing to disclose