Increased dose efficiency of breast CT with grating interferometry

Abstract

Refraction-based x-ray imaging can overcome the fundamental contrast limit of computed tomography (CT), particularly in soft tissue, but so far has been constrained to high-dose ex vivo applications or required highly coherent x-ray sources, such as synchrotrons. Here we demonstrate that grating interferometry (GI) is more dose efficient than conventional CT in imaging of human breast under close-to-clinical conditions. Our system, based on a conventional source and commercial gratings, outperformed conventional CT for spatial resolutions better than 263 µm and absorbed dose of 16 mGy. The sensitivity of GI is constrained by grating fabrication, and further progress will lead to significant improvements of clinical CT.