TY - JOUR
T1 - The effect of different image reconstruction techniques on pre-clinical quantitative imaging and dual-energy CT
AU - Vaniqui, Ana
AU - Schyns, Lotte E. J. R.
AU - Almeida, Isabel P.
AU - van der Heyden, Brent
AU - Podesta, Mark
AU - Verhaegen, Frank
N1 - Funding Information:
AV acknowledges financial support from CAPES Scholarship and Science without Borders program from Brazil (BEX 12030/13–9).
Publisher Copyright:
© 2019 The Authors. Published by the British Institute of Radiology
PY - 2019
Y1 - 2019
N2 - Objective: To analyse the effect of different image reconstruction techniques on image quality and dual energy CT (DECT) imaging metrics.Methods: A software platform for pre-clinical cone beam CT X-ray image reconstruction was built using the open-source reconstruction toolkit. Pre-processed projections were reconstructed with filtered back-projection and iterative algorithms, namely Feldkamp, Davis, and Kress (FDK), Iterative FDK, simultaneous algebraic reconstruction technique (SART), simultaneous iterative reconstruction technique and conjugate gradient. Imaging metrics were quantitatively assessed, using a quality assurance phantom, and DECT analysis was performed to determine the influence of each reconstruction technique on the relative electron density (rho(e)) and effective atomic number (Z(eff)) values.Results: Iterative reconstruction had favourable results for the DECT analysis: a significantly smaller spread for each material in the rho(e)-Z(eff) space and lower Z(eff) and rho(e) residuals (on average 24 and 25% lower, respectively). In terms of image quality assurance, the techniques FDK, Iterative FDK and SART provided acceptable results. The three reconstruction methods showed similar geometric accuracy, uniformity and CT number results. The technique SART had a contrast-to-noise ratio up to 76% higher for solid water and twice as high for Teflon, but resolution was up to 28% lower when compared to the other two techniques.Conclusions: Advanced image reconstruction can be beneficial, but the benefit is small, and calculation times may be unacceptable with current technology. The use of targeted and downscaled reconstruction grids, larger, yet practicable, pixel sizes and GPU are recommended.Advances in knowledge: An iterative CBCT reconstruction platform was build using RTK.
AB - Objective: To analyse the effect of different image reconstruction techniques on image quality and dual energy CT (DECT) imaging metrics.Methods: A software platform for pre-clinical cone beam CT X-ray image reconstruction was built using the open-source reconstruction toolkit. Pre-processed projections were reconstructed with filtered back-projection and iterative algorithms, namely Feldkamp, Davis, and Kress (FDK), Iterative FDK, simultaneous algebraic reconstruction technique (SART), simultaneous iterative reconstruction technique and conjugate gradient. Imaging metrics were quantitatively assessed, using a quality assurance phantom, and DECT analysis was performed to determine the influence of each reconstruction technique on the relative electron density (rho(e)) and effective atomic number (Z(eff)) values.Results: Iterative reconstruction had favourable results for the DECT analysis: a significantly smaller spread for each material in the rho(e)-Z(eff) space and lower Z(eff) and rho(e) residuals (on average 24 and 25% lower, respectively). In terms of image quality assurance, the techniques FDK, Iterative FDK and SART provided acceptable results. The three reconstruction methods showed similar geometric accuracy, uniformity and CT number results. The technique SART had a contrast-to-noise ratio up to 76% higher for solid water and twice as high for Teflon, but resolution was up to 28% lower when compared to the other two techniques.Conclusions: Advanced image reconstruction can be beneficial, but the benefit is small, and calculation times may be unacceptable with current technology. The use of targeted and downscaled reconstruction grids, larger, yet practicable, pixel sizes and GPU are recommended.Advances in knowledge: An iterative CBCT reconstruction platform was build using RTK.
KW - MICRO-CT
KW - BRACHYTHERAPY
KW - RADIOTHERAPY
KW - SIMULATION
KW - ACCURACY
KW - NUMBERS
KW - ART
U2 - 10.1259/bjr.20180447
DO - 10.1259/bjr.20180447
M3 - Article
C2 - 30394804
SN - 0007-1285
VL - 92
JO - British Journal of Radiology
JF - British Journal of Radiology
IS - 1095
M1 - 20180447
ER -