Visualising Parker Weighting in Short-Scan Cone-Beam Micro-CT: A Practical Reference

TL;DR

This paper provides a visual and quantitative guide to Parker weighting in short-scan cone-beam micro-CT, demonstrating its effectiveness in correcting artefacts and HU inaccuracies without degrading image quality.

Contribution

It offers a practical reference with visualizations and analyses of Parker weighting implementation for the eXplore CT 120 scanner, aiding in its adoption and evaluation.

Findings

Parker weighting corrects shading artefacts in short-scan micro-CT images.

HU inaccuracies are mitigated without degrading image quality.

Visual and quantitative summaries facilitate implementation and evaluation.

Abstract

Short-scan FDK reconstruction is widely used in preclinical cone-beam micro-CT because it reduces scan time and radiation dose, and because the large volume sizes typical of micro-CT make iterative methods impractical for routine use. Short scans, however, introduce non-uniform data redundancy that must be corrected by Parker weighting to avoid directional shading artefacts. This note provides a visual and quantitative summary of Parker weighting as implemented for the eXplore CT 120 scanner. We illustrate the weight maps in the detector and sinogram domains, demonstrate the shading artefacts that arise without correction on both an image quality phantom and an in vivo mouse lung, and show via MTF, NPS, and detectability analysis that Parker weighting corrects HU inaccuracies without degrading image quality. No new methods are introduced; the aim is to serve as a concise practical reference for groups implementing or evaluating short-scan FDK pipelines.