TY - GEN
T1 - Cascaded systems analysis of the 3D NEQ for cone-beam CT and tomosynthesis
AU - Tward, D. J.
AU - Siewerdsen, J. H.
AU - Fahrig, R. A.
AU - Pineda, A. R.
PY - 2008
Y1 - 2008
N2 - Crucial to understanding the factors that govern imaging performance is a rigorous analysis of signal and noise transfer characteristics (e.g., MTF, NPS, and NEQ) applied to a task-based performance metric (e.g., detectability index). This paper advances a theoretical framework for calculation of the NPS, NEQ, and DQE of cone-beam CT (CBCT) and tomosynthesis based on cascaded systems analysis. The model considers the 2D projection NPS propagated through a series of reconstruction stages to yield the 3D NPS, revealing a continuum (from 2D projection radiography to limitedangle tomosynthesis and fully 3D CBCT) for which NEQ and detectability index may be investigated as a function of any system parameter. Factors considered in the cascade include: system geometry; angular extent of source-detector orbit; finite number of views; log-scaling; application of ramp, apodization, and interpolation filters; back-projection; and 3D noise aliasing - all of which have a direct impact on the 3D NEQ and DQE. Calculations of the 3D NPS were found to agree with experimental measurements across a broad range of imaging conditions. The model presents a theoretical framework that unifies 3D Fourier-based performance metrology in tomosynthesis and CBCT, providing a guide to optimization that rigorously considers the system configuration, reconstruction parameters, and imaging task.
AB - Crucial to understanding the factors that govern imaging performance is a rigorous analysis of signal and noise transfer characteristics (e.g., MTF, NPS, and NEQ) applied to a task-based performance metric (e.g., detectability index). This paper advances a theoretical framework for calculation of the NPS, NEQ, and DQE of cone-beam CT (CBCT) and tomosynthesis based on cascaded systems analysis. The model considers the 2D projection NPS propagated through a series of reconstruction stages to yield the 3D NPS, revealing a continuum (from 2D projection radiography to limitedangle tomosynthesis and fully 3D CBCT) for which NEQ and detectability index may be investigated as a function of any system parameter. Factors considered in the cascade include: system geometry; angular extent of source-detector orbit; finite number of views; log-scaling; application of ramp, apodization, and interpolation filters; back-projection; and 3D noise aliasing - all of which have a direct impact on the 3D NEQ and DQE. Calculations of the 3D NPS were found to agree with experimental measurements across a broad range of imaging conditions. The model presents a theoretical framework that unifies 3D Fourier-based performance metrology in tomosynthesis and CBCT, providing a guide to optimization that rigorously considers the system configuration, reconstruction parameters, and imaging task.
KW - 3D imaging, imaging performance
KW - Cascaded systems analysis
KW - Cone-beam CT
KW - Flat-panel detector
KW - NEQ
KW - NPS
KW - Noise-equivalent quanta
KW - Noise-power spectrum
KW - Tomosynthesis
UR - http://www.scopus.com/inward/record.url?scp=43149120917&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=43149120917&partnerID=8YFLogxK
U2 - 10.1117/12.772999
DO - 10.1117/12.772999
M3 - Conference contribution
AN - SCOPUS:43149120917
SN - 9780819470973
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Medical Imaging 2008 - Physics of Medical Imaging
T2 - Medical Imaging 2008 - Physics of Medical Imaging
Y2 - 18 February 2008 through 21 February 2008
ER -