Quantification for contrast-enhanced digital breast tomosynthesis

Abstract

Digital breast tomosynthesis (DBT) is a tomographic technique in which individual slices through the breast are reconstructed from x-ray projection images acquired over a limited angular range. In contrast-enhanced DBT (CE-DBT) functional information can be observed by administration of an x-ray contrast agent. We have investigated the technical requirements necessary to quantitatively analyze CE-DBT exams. Using a simplified physiological model, a maximum aerial concentration of approximately 2.2 mg iodine/cm² in a 0.5 cm thick breast lesion is expected when administering 70 ml of 320 mg iodine/ml Visipaque-320^®. This corresponds to a small change in x-ray transmission; up to 5% for a 4 cm thick compressed breast. We have modeled CE-DBT acquisition by simulating Rh target x-ray spectra from 40 to 49 kV. Comparison of attenuation data of our simulated and measured spectra were found to agree well. We investigated the effect of scatter, patient motion and temporal stability of the detector on quantifying iodine uptake. These parameters were evaluated by means of experiments and theoretical modeling.