An approximation formula for the variance of PET region-of-interest values

Author

Carson, R.E. ; Yan, Y. ; Daube-Witherspoon, M.E. ; Freedman, N. ; Bacharach, S.L. ; Herscovitch, P.

Author_Institution

PET Dept., Nat. Inst. of Health, Bethesda, MD, USA

Volume

12

Issue

2

fYear

1993

fDate

6/1/1993 12:00:00 AM

Firstpage

240

Lastpage

250

Abstract

An approximation formula for the variance of positron emission tomography (PET) region-of-interest (ROI) values has been developed, implemented, and evaluated. This formula does not require access to the original projection data and is therefore convenient for routine use. The formula was derived by applying successive approximations to the filtered-backprojection reconstruction algorithm. ROI variance is estimated from the product of mean pixel variance within the region and a term accounting for the intercorrelation of all pixel pairs inside the region. The formula accounts for radioactivity distribution, attenuation, randoms, scatter, deadtime, detector normalization, scan length, decay, and reconstruction filter. The algorithm was tested by comparison to the exact ROI variance as calculated with Huesman´s algorithm. Tests with scan data from phantoms, animals, and humans obtained on the Scanditronix PC2048-15B tomograph showed the approximation formula to be accurate to within ±10%

Keywords

computerised tomography; radioisotope scanning and imaging; PET region-of-interest values; Scanditronix PC2048-15B tomograph; algorithm; animals; approximation formula; detector normalization; humans; mean pixel variance; medical diagnostic imaging; nuclear medicine; phantoms; positron emission tomography; radioactivity distribution; reconstruction filter; scan length; Animals; Attenuation; Detectors; Filters; Humans; Imaging phantoms; Positron emission tomography; Reconstruction algorithms; Scattering; Testing;

fLanguage

English

Journal_Title

Medical Imaging, IEEE Transactions on

Publisher

ieee

ISSN

0278-0062

Type

jour

DOI

10.1109/42.232252

Filename

232252