Breast-density measurement using photon-counting spectral mammography

Abstract

Purpose: To evaluate a method for measuring breast density using photon-counting spectral mammography. Breast density is an indicator of breast cancer risk and diagnostic accuracy in mammography, and can be used as input to personalized screening, treatment monitoring and dose estimation. Methods: The measurement method employs the spectral difference in x-ray attenuation between adipose and fibro-glandular tissue, and does not rely on any a priori information. The method was evaluated using phantom measurements on tissue-equivalent material (slabs and breast-shaped phantoms) and using clinical data from a screening population (n ¼ 1329). A state-of-the-art nonspectral method for breast-density assessment was used for benchmarking. Results: The precision of the spectral method was estimated to be 1.5-1.8 percentage points (pp) breast density. Expected correlations were observed in the screening population for thickness versus breast density, dense volume, breast volume, and compression height. Densities ranged between 4.5% and 99.6%, and exhibited a skewed distribution with a mode of 12.5%, a median of 18.3%, and a mean of 23.7%. The precision of the nonspectral method was estimated to be 2.7-2.8 pp. The major uncertainty of the nonspectral method originated from the thickness estimate, and in particular thin/dense breasts posed problems compared to the spectral method. Conclusions: The spectral method yielded reasonable results in a screening population with a precision approximately two times that of the nonspectral method, which may improve or enable applications of breast-density measurement on an individual basis such as treatment monitoring and personalized screening.

Breast density: why all the fuss?

“…Spectral mammography with energy-resolved photon counting detectors eliminates the need for two exposures, reducing radiation dose. A recent comparative study using BIRADS, Cumulus, a fuzzy C-means segmentation and spectral mammography material decomposition showed excellent right-left correlation for the latter, with much higher precision than for the other techniques (142), an observation replicated in a recent study from Sweden (143).…”

Cascaded systems analysis of charge sharing in cadmium telluride photon‐counting x‐ray detectors

“…Spectroscopic x‐ray imaging detectors are under development in academic and industry laboratories. Advantages of spectroscopic detectors over energy‐integrating detectors include improved dose efficiency and the potential for single‐exposure, material‐specific imaging …”

Sensitivity-based optimization for the design of a grating interferometer for clinical X-ray phase contrast mammography

“…The highest-occurrence (25.9 %) breast corresponds to an average compression thickness of 7 cm and a glandular density of 18.1 %. The breast density values were calculated with the built-in breast-density measurement tool in the Philips system, for which the spectral image data was decomposed into volumes of glandular and adipose tissue by calibration on tissue-equivalent material [30][31][32]. The attenuation coefficient of this target breast was calculated using the XCOM photon cross section database of the National Institute of Standards and Technology (NIST) [33], utilizing the breast adipose and glandular tissue compositions defined by the International Commission on Radiation Units and Measurements (ICRU) in report 46.…”