A new method for phase contrast tomography

Abstract

We report how a method which requires a simple experimental setup, in principle equivalent to the one for doing classical absorption tomography, can yield phase information in three dimensions in only one single step. As an alternative to two steps approaches (phase retrieval and reconstruction of the object function applying a conventional filtered backprojection algorithm), A.V. Bronnikov suggested an algorithm which provides direct 3D reconstruction of the refractive index from the intensity distributions measured in a single plane (pure phase object) and from the intensity distributions measured in two planes (mixed phase-amplitude object). We adapted the original algorithm in order to retrieve the 3D reconstruction of the refractive index from the intensity distributions measured in a single plane also for the case of mixed weakly absorbing-phase object. The results show that the contrast is increased, while keeping dose minimal and spatial resolution equivalent to the conventional absorption based technique. © 2007 American Institute of Physics.