Performance evaluation of a digital mammography unit using a contrast-detail phantom

7th International Congress of Engineering Physics

物理学;工业技术

Elizalde-Cabrera, J.^1 ; Brandan, M.-E.^1

Instituto de Física, Universidad Nacional Autónoma de México, Ciudad Universitaria, México DF

04510, Mexico^1

关键词: Analysis of signal;    Automatic exposure controls;    Contrast-detail curve;    Digital mammography;    Flattening process;    Mean glandular dose;    Performance evaluations;    Radiological technique;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/582/1/012036/pdf
DOI  :  10.1088/1742-6596/582/1/012036

学科分类：工业工程学

来源: IOP

【 摘 要 】

The relation between image quality and mean glandular dose (MGD) has been studied for a Senographe 2000D mammographic unit used for research in our laboratory. The magnitudes were evaluated for a clinically relevant range of acrylic thicknesses and radiological techniques. The CDMAM phantom was used to determine the contrast-detail curve. Also, an alternative method based on the analysis of signal-to-noise (SNR) and contrast-to-noise (CNR) ratios from the CDMAM image was proposed and applied. A simple numerical model was utilized to successfully interpret the results. Optimum radiological techniques were determined using the figures-of-merit FOMSNR=SNR2/MGD and FOMCNR=CNR2/MGD. Main results were: the evaluation of the detector response flattening process (it reduces by about one half the spatial non-homogeneities due to the X- ray field), MGD measurements (the values comply with standards), and verification of the automatic exposure control performance (it is sensitive to fluence attenuation, not to contrast). For 4-5 cm phantom thicknesses, the optimum radiological techniques were Rh/Rh 34 kV to optimize SNR, and Rh/Rh 28 kV to optimize CNR.