Microbubbles as a contrast agent in grating interferometry mammography: an ex vivo proof-of-mechanism study

• Main Authors: Kristina Lång, Carolina Arboleda, Serafino Forte, Zhentian Wang, Sven Prevrhal, Thomas Koehler, Norbert Kuhn, Bernd David, Konstantins Jefimovs, Rahel A. Kubik-Huch, Marco Stampanoni
• Format: Article
• Language: English
• Published: SpringerOpen 2019-05-01
• Series: European Radiology Experimental
• Subjects: Contrast media; Interferometry; Mammography; Microbubbles; Phantoms (imaging)
• Online Access: http://link.springer.com/article/10.1186/s41747-019-0097-2

Abstract Grating interferometry mammography (GIM) is an experimental breast imaging method at the edge of being clinically implemented. Besides attenuation, GIM can measure the refraction and scattering of x-rays resulting in differential phase contrast (DPC) and dark-field (DF) images. In this exploratory study, we assessed the feasibility of using microbubbles as a contrast agent in GIM. Two millilitres of microbubbles and iodine were respectively injected into ex vivo breast phantoms, consisting of fresh chicken breasts. Native and postcontrast images were acquired with a clinically compatible GIM setup, operated at 38 kVp, 14-s acquisition time, and with a dose of 1.3 mGy. The visibility of the contrast agents was analysed in a side-by-side comparison by three radiologists. The contrast-to-noise-ratio (CNR) was calculated for each contrast agent. We found that both contrast agents were judged to be visible by the readers. The mean CNR was 3.1 ± 1.9 for microbubbles in DF and 24.2 ± 6.5 for iodine in attenuation. In conclusion, this is a first proof-of-mechanism study that microbubbles could be used as a contrast agent in clinically compatible GIM, due to their scattering properties, which implies the potential use of a contrast agent with a high safety profile in x-ray-based breast imaging.