Experimental demonstration of ultrahigh sensitivity Talbot-Lau interferometer for low dose mammography


N. Safca, D. Stutman, E. Anghel, F. Negoita, and C.A.Ur [ https://iopscience.iop.org/article/10.1088/1361-6560/aca514 ]

Even though the techniques used for breast cancer identification have advanced over the years, current mammography based on X-rays absorption, the "gold standard" screening test at present, still has some shortcomings as concerns sensitivity and specificity to early-stage cancers, due to poor differentiation between tumor and normal tissues, especially in the case of the dense breasts. In this paper, we investigate a possible additional technique for breast cancer detection with higher sensitivity and low dose, X-ray phase-contrast or refraction-based imaging with ultrahigh angular sensitivity grating interferometers, having several meters length.
The results reported in our paper confirm the ultrahigh sensitivity and dose economy possible with our setup. The visibility of objects simulating cancerous formations is strongly increased in the refraction images over the attenuation ones, even at a low dose of 0.32 mGy. Our experiments on a mammography phantom illustrate the capabilities of the proposed technique and can open the way toward low-dose interferometric laser-based mammography.

Absorption mammography (65 cm long setup) images (a), (b), (c) at 100 mAs and interferometric mammography (5.7 m long setup) refraction angle images (d), (e), (f) of fibrils in the GAMMEX 156 phantom, obtained at a dose of 2.73 mGy, as calculated with the above procedure. Also shown absorption mammography (g), (h), (i) and interferometric mammography dark-field images (j), (k), (l) of specs simulating calcifications. The object size is indicated above each image. The intensity scale in the absorption images is 90%-105% of the mean count value, and the scale in the refraction angle image is from -1 to +1 microradian. The scale in the dark-field image is between 35%-42% of the visibility of the stepping curve (calculated as the ratio between the average value of the stepping curve in the presence of the sample and the visibility of a reference scan).

Ultrahigh sensitivity long Talbot-Lau interferometer for interferometric mammography.