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
Methods and materials
A prototype for a multi-energy X-ray detector was built,
consisting of three stacked sensitive layers that will each simultaneously generate a digital image and serve as a beam-hardening filter for the subsequent layer.
Each layer consisted of a scintillator-based flat-panel sensor.
DR images were reconstructed by summing all layers’ images,
while tissue-subtracted images were generated using logarithmic subtraction.
Unlike conventional single-shot detectors,
this design does not require the use a metal mid-filter.
it enables the potential for high dose efficiency while maintaining a good spectral separation.
the additional data point of the middle sensor allows for more sophisticated subtraction and correction algorithms.
To evaluate the feasibility of this detector and technique to generate tissue-subtracted images,
an anatomical chest phantom (Lungman,
Kyoto Kagaku Co.) was imaged and the resulting soft- and hard-tissue images were subjectively analyzed for subtraction quality.
Said metric includes both the amount of anatomical noise cancellation as well as its uniformity across the entire image.
The DR capabilities of the detector were measured using detective quantum efficiency (DQE) as the metric of choice.