Investigating Oblique Reconstructions with Super-Resolution in Digital Breast Tomosynthesis

Abstract

In digital breast tomosynthesis (DBT), the image of an object is shifted in sub-pixel detector element increments with each increasing projection angle. As a consequence of this property, we have previously demonstrated that DBT is capable of super-resolution in reconstruction planes parallel to the breast support. This study demonstrates that super-resolution is also achievable in obliquely pitched reconstruction planes. To this end, a theoretical framework is developed in which the reconstruction of a sinusoidal input is calculated. It is demonstrated that frequencies exceeding the detector alias frequency can be resolved over many pitches. For experimental validation of this finding, a bar pattern phantom was imaged on a goniometry stand using a commercial DBT system. With a commercial prototype reconstruction solution, high frequency patterns were resolved in oblique reconstructions, and modulation contrast was determined at various pitches and frequencies. This work demonstrates the existence of super-resolution in oblique DBT reconstructions.