Analytic variance estimates of Swank and Fano factors. Issue 7 (18th June 2014)

• Record Type: Journal Article
• Authors: Gutierrez, Benjamin; Badano, Aldo; Samuelson, Frank
• Is Part Of: Medical physics. Volume 41:Issue 7(2014)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2014-06-18
• Subjects: Monte Carlo simulations -- Distribution theory and Monte Carlo studies -- X‐ and γ‐ray sources, mirrors, gratings, and detectors -- Biomedical instrumentation and transducers, including micro‐electro‐mechanical systems (MEMS); biomedical equipment -- Monte Carlo methods -- statistical analysis -- X‐ray detection; Swank Factor -- Fano factor -- variance -- Monte Carlo simulation; Biological material, e.g. blood, urine; Haemocytometers -- Devices sensitive to very short wavelength, e.g. x‐rays, gamma‐rays or corpuscular radiation -- Transforming x‐rays -- X‐ray technique; Monte Carlo methods -- X‐ray detectors -- Data sets -- Scintillation detectors -- Statistical properties -- Computer software -- X‐ray imaging -- Particle beam detectors; Medical physics -- Periodicals; Medical physics; Geneeskunde; Natuurkunde; Toepassingen; Biophysics; Periodicals; Periodicals; Electronic journals; 610.153
• DOI: 10.1118/1.4881328
• Languages: English
• ISSNs: 0094-2405

Abstract

Abstract : Purpose: Variance estimates for detector energy resolution metrics can be used as stopping criteria in Monte Carlo simulations for the purpose of ensuring a small uncertainty of those metrics and for the design of variance reduction techniques. Methods: The authors derive an estimate for the variance of two energy resolution metrics, the Swank factor and the Fano factor, in terms of statistical moments that can be accumulated without significant computational overhead. The authors examine the accuracy of these two estimators and demonstrate how the estimates of the coefficient of variation of the Swank and Fano factors behave with data from a Monte Carlo simulation of an indirect x‐ray imaging detector. Results: The authors' analyses suggest that the accuracy of their variance estimators is appropriate for estimating the actual variances of the Swank and Fano factors for a variety of distributions of detector outputs. Conclusions: The variance estimators derived in this work provide a computationally convenient way to estimate the error or coefficient of variation of the Swank and Fano factors during Monte Carlo simulations of radiation imaging systems.