An efficient pre-object collimator based on an x-ray lens

TL;DR

This paper introduces a multi-prism x-ray lens used as a pre-object collimator in medical imaging, demonstrating improved flux and resolution in prototype mammography systems.

Contribution

It presents the first images with an MPL in a scanning mammography prototype, showing significant flux and resolution gains over traditional slit collimators.

Findings

Flux gain of 1.32 compared to slit collimator

Resolution gain of 1.31-1.44 at equal flux

Projected flux gain of 1.67 in clinical setups

Abstract

A multi-prism lens (MPL) is a refractive x-ray lens with one-dimensional focusing properties. If used as a pre-object collimator in a scanning system for medical x-ray imaging, it reduces the divergence of the radiation and improves on photon economy compared to a slit collimator. Potential advantages include shorter acquisition times, a reduced tube loading, or improved resolution. We present the first images acquired with an MPL in a prototype for a scanning mammography system. The lens showed a gain of flux of 1.32 compared to a slit collimator at equal resolution, or a gain in resolution of 1.31-1.44 at equal flux. We expect the gain of flux in a clinical set-up with an optimized MPL and a custom-made absorption filter to reach 1.67, or 1.45-1.54 gain in resolution.