Abstract
Motion during data acquisition is a known source of error in medical tomography, resulting in blur artefacts in the regions that move. It is critical to reduce these artefacts in applications such as image-guided radiation therapy as a clearer image translates into a more accurate treatment and the sparing of healthy tissue close to a tumour site. Most research in 4D x-ray tomography involving the thorax relies on respiratory phase binning of the acquired data and reconstructing each of a set of images using the limited subset of data per phase. In this work, we demonstrate a motion-compensation method to reconstruct images from the complete dataset taken during breathing without recourse to phase-binning or breath-hold techniques. As long as the motion is sufficiently well known, the new method can accurately reconstruct an image at any time during the acquisition time span. It can be applied to any iterative reconstruction algorithm.
Highlights
Organ movement can be a serious problem in x-ray imaging as the inconsistency between data taken at different phases of the motion leads to blurring and makes the boundaries between different regions hard to distinguish. This effect is important in image-guided radiation therapy (IGRT), especially for tumours located in the thorax, such as lung or liver
We have demonstrated a significant improvement in cone-beam computed tomography (CBCT) image quality by removing motion artifacts using a modelling approach to motion compensation
The method requires a knowledge of the deformation vector fields describing the motion between the reconstructed state and all others during the acquisition time span
Summary
Organ movement can be a serious problem in x-ray imaging as the inconsistency between data taken at different phases of the motion leads to blurring and makes the boundaries between different regions hard to distinguish. This effect is important in image-guided radiation therapy (IGRT), especially for tumours located in the thorax, such as lung or liver. Nowadays the principal clinical solution to ensure the irradiation of all the tumour is to irradiate the entire region where it is estimated to be located during the full respiratory cycle, necessarily damaging some healthy tissue. This is even more critical in hadron therapy because, unlike photons, charged particles deposit most of their energy at the Bragg peak, which means a tumour could be missed completely and only healthy tissue irradiated if targeting is carried out on the basis of inaccurate treatment planning
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
