Signal and noise transfer in spatiotemporal quantum-based imaging systems.
Fourier-based transfer theory is extended into the temporal domain to describe both spatial and temporal noise processes in quantum-based medical imaging systems. Lag is represented as a temporal scatter in which the release of image quanta is delayed according to a probability density function. Expressions describing transfer of the spatiotemporal Wiener noise power spectrum through quantum gain and scatter processes are derived. Lag introduces noise correlations in the temporal domain in proportion to the correlated noise component only. The effect of lag is therefore dependent on both spatial and temporal physical processes. A simple model of a fluoroscopic system shows that image noise is reduced by a factor that is similar to Wagner's information bandwidth integral, which depends on the temporal modulation transfer function.
Robarts Research Institute, Department of Medical Biophysics, University of Western Ontario, 100 Perth Drive,London, Ontario, Canada.
Reza
R
Akbarpour
Saul N
SN
Friedman
Jeffrey H
JH
Siewerdsen
John D
JD
Neary
Ian A
IA
Cunningham
D016477:Artifacts; D003627:Data Interpretation, Statistical; D005471:Fluoroscopy / Q000379:methods; D005583:Fourier Analysis; D007257:Information Theory; D011789:Quantum Theory; D011856:Radiographic Image Enhancement; D012016:Reference Values; D012542:Scattering, Radiation; D012815:Signal Processing, Computer-Assisted; D013269:Stochastic Processes; D013679:Technology, Radiologic / Q000379:methods; D013995:Time; D013997:Time Factors; D014965:X-Rays