Equal-dose spectral optimization of spectral CT mono-energy photon counting

Autor: Daniel David Harrison, Vladimir A. Lobastov, Pete Edic, J. Eric Tkaczyk, Hewei Gao, Daniel Rubin
Rok vydání: 2012
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.912113
Popis: The image quality entitlement is evaluated for multi-energy bin photon counting (PC) spectral CT relative to that of energy integration an dual kVp (dkVp) imaging. Physics simulations of X-ray projection channel data and CT images are used to map contrast-to-noise metrics for simple numerical phantoms objects with soft tissue, calcium and iodine materials. The benefits are quantified under ideal detector conditions. Spectral optimization yields on the order of 2X benefit for iodine visualization measured by CNR^2/dose in two different imaging modes: optimal energy weighting, and optimal mono-energy imaging. In another case studied, strict dose equivalence is maintained by use of a composite spectrum for PC simulation that combines simultaneously the two kVp excitations used sequentially for dkVp. In this case, mono-energetic imaging of iodine contrast agent is shown to achieve 40% higher dose efficiency for photon counting compared to dual kVp although non-ideal characteristics of the photon counting response can eliminate much of this benefit.
Databáze: OpenAIRE