Tomosynthesis method for depth resolution of beta emitters.

The motivation of this study derives from the need for tumour margin estimation after surgical excision. Conventional beta autoradiography of beta emitters can be used to image tissue sections providing high spatial resolution compared to in-vivo molecular imaging. However, it requires sectioning of the specimen and it provides a 2D image of the tissue. Imaging of the 3D tissue sample can be achieved either by imaging sequential 2D sections, which is time-consuming and laborious, or by using a specialised detector for imaging that records the particles' direction, in addition to their position, when they hit the detector. In this work we investigate whether a novel beta-tomosynthesis approach can be used for depth resolution of beta emitters. The technique involves acquiring multiple 2D images of the intact tissue sample while the detector rotates around the sample. The images are then combined and used to reconstruct the 3D position of the sources from a limited angle of conventional 2D autoradiography images. We present the results from Geant4 forward simulations and the reconstructed images from a breast tissue sample containing a Fluorine-18 positron emission source. The experiments show that the proposed method can provide depth resolution under certain conditions, indicating that there is potential for its use as a 3D molecular imaging technique of surgical samples in the future.