Lung, Digital radiography, Image manipulation / Reconstruction, Diagnostic procedure, Physics
S. Lopez Maurino1, S. Ghanbarzadeh1, S. Ghaffari1, K. S. Karim2; 1Kitchener, ON/CA, 2Waterloo, ON/CA
Aims and objectives
Dual-energy (DE) radiography is a technique that can remove specific anatomical noise from a radiograph and generate tissue-subtracted images.
a trio of images is presented comprised of a standard digital radiography (DR) image,
a soft-tissue image –where the bone clutter has been removed,– and a bone image –where the soft tissue is not present.
Such a technique is of particular interest in chest radiography,
where the detection of lung nodules has been shown to be primarily limited by anatomical noise.
the use of DE imaging aids by presenting a soft-tissue image without bone clutter thereby increase nodule conspicuity.
Many studies have shown that this leads to increased nodule detectability[2–6].
DE imaging can help characterize lung lesions since nodule calcification is an indicator of benignancy.
This is achieved by studying the bone-only image,
which has been shown to be an effective way of evaluating nodule calcification.
DE chest radiography has also shown potential in scoring of coronary artery calcium[8,9].
two distinct technologies exist to obtain DE images.
The more common is that of a dual-shot system,
where two separate exposures of the patient are quickly taken at different source peak voltages.
While this technique achieves excellent spectral separation,
the temporal separation between the two exposures invariably leads to motion artifacts in the tissue-subtracted images.
tight integration with a fast-switching source is required,
restricting its availability to fixed systems.
The alternative DE technique is a single-shot system,
where a detector composed of two sensitive layers separated by a metal mid-filter is used.
Two images at different input spectra are obtained thanks to the beam hardening properties of the mid-filter.
This technique is immune to motion artifacts and offers ample system flexibility since all the DE capabilities come from the detector,
but results in poorer spectral separation and lower dose efficiency in its DR images due to the signal lost in the filter.
built and tested a novel single-shot,
multi-energy flat-panel stacked X-ray detector that aims to expand on the capabilities of current single-shot systems by reducing or removing its shortcomings.
it can potentially achieve good spectral separation and high DR dose efficiency in a single-shot system.
The purpose of this study is to evaluate the feasibility of such a detector as an alternative to established DE systems for the acquisition of both DE and DR images.