Orientation dependent detectability of fiber-like signals in linear iterative image reconstruction for breast tomosynthesis

Abstract

We characterize the detectability of fiber-like signals in digital breast tomosynthesis (DBT) for linear iterative image reconstruction (IIR) algorithms. The detectability is investigated as a function of signal orientation and IIR regularization strength. The detectability is computed with a region-of-interest (ROI) Hotelling observer (HO) and applied to two linear IIR algorithms. Trends in detectability are compared with conspicuity of signals reconstructed in both simulation and real data studies. A common trend is observed with both algorithms in which signals oriented parallel to the detector and the plane containing the source-trajectory have lower detectability than their orthogonal counterparts at low regularization strengths. The orientation dependence is gradually reduced with increasing regularization strength. These trends in detectability are seen to match well with trends in the conspicuity of reconstructed signals in both simulation and real data studies.