@inproceedings{e22703fa0902479690fd68d3ae0b452c,
title = "Over-exposure correction in knee cone-beam CT imaging with automatic exposure control using a partial low dose scan",
abstract = "C-arm-based cone-beam CT (CBCT) systems with flat-panel detectors are suitable for diagnostic knee imaging due to their potentially flexible selection of CT trajectories and wide volumetric beam coverage. In knee CT imaging, over-exposure artifacts can occur because of limitations in the dynamic range of the flat panel detectors present on most CBCT systems. We developed a straightforward but effective method for correction and detection of over-exposure for an Automatic Exposure Control (AEC)-enabled standard knee scan incorporating a prior low dose scan. The radiation dose associated with the low dose scan was negligible (0.0042mSv, 2.8% increase) which was enabled by partially sampling the projection images considering the geometry of the knees and lowering the dose further to be able to just see the skin-air interface. We combined the line integrals from the AEC and low dose scans after detecting over-exposed regions by comparing the line profiles of the two scans detector row-wise. The combined line integrals were reconstructed into a volumetric image using filtered back projection. We evaluated our method using in vivo human subject knee data. The proposed method effectively corrected and detected over-exposure, and thus recovered the visibility of exterior tissues (e.g., the shape and density of the patella, and the patellar tendon), incorporating a prior low dose scan with a negligible increase in radiation exposure.",
keywords = "Automatic Exposure Control, C-arm CT, Cone-beam CT, Detector over-exposure, Detector saturation, Flat-panel detector, Knee CT imaging, Lower extremity",
author = "Choi, {Jang Hwan} and Kerstin Muller and Scott Hsieh and Andreas Maier and Garry Gold and Marc Levenston and Rebecca Fahrig",
note = "Funding Information: This work was supported by NIH R01 AR065248, NIH Shared Instrument Grant S10 RR026714, and Siemens AX. This work was never submitted, published, or presented before. Publisher Copyright: {\textcopyright} 2016 SPIE.; Medical Imaging 2016: Physics of Medical Imaging ; Conference date: 28-02-2016 Through 02-03-2016",
year = "2016",
doi = "10.1117/12.2217347",
language = "English",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
publisher = "SPIE",
editor = "Despina Kontos and Lo, {Joseph Y.} and Flohr, {Thomas G.}",
booktitle = "Medical Imaging 2016",
}