A method for point spread function estimation for accurate quantitative imaging

• Verfasst von: Attarwala, Ali Asgar [VerfasserIn]
• Verfasst von: Wängler, Björn [VerfasserIn]
• Titel: A method for point spread function estimation for accurate quantitative imaging
• Verf.angabe: A.A. Attarwala, D. Hardiansyah, C. Romanó, M. Roscher, F. Molina-Duran, B. Wängler, and G. Glatting
• E-Jahr: 2018
• Jahr: March 2018
• Umfang: 9 S.
• Fussnoten: Gesehen am 04.06.2020
• Titel Quelle: Enthalten in: Institute of Electrical and Electronics EngineersIEEE transactions on nuclear science
• Ort Quelle: New York, NY : IEEE, 1963
• Jahr Quelle: 2018
• Band/Heft Quelle: 65(2018), 3, Seite 961-969
• ISSN Quelle: 1558-1578
• DOI: doi:10.1109/TNS.2018.2806843
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: 1-Gauss
• Sach-SW: 3D fitting functions
• Sach-SW: 3D Gaussian function
• Sach-SW: Akaike information criterion
• Sach-SW: Akaike information criterion (AIC)
• Sach-SW: Detectors
• Sach-SW: Estimation
• Sach-SW: expectation-maximisation algorithm
• Sach-SW: Fitting
• Sach-SW: full-width at half-maximum
• Sach-SW: FWHMs
• Sach-SW: Gaussian function
• Sach-SW: image reconstruction
• Sach-SW: Image reconstruction
• Sach-SW: image resolution
• Sach-SW: Imaging
• Sach-SW: MATLAB-based mathematical source simulation
• Sach-SW: maximum-likelihood expectation-maximization algorithm
• Sach-SW: measured data reconstruction
• Sach-SW: medical image processing
• Sach-SW: National Electrical Manufacturing Association (NEMA)
• Sach-SW: National Electrical Manufacturing Association NU4 2008 protocol
• Sach-SW: NEMA method
• Sach-SW: NU4
• Sach-SW: optical transfer function
• Sach-SW: phantoms
• Sach-SW: pixel size
• Sach-SW: point spread function (PSF)
• Sach-SW: point spread function estimation
• Sach-SW: single photon emission computed tomography
• Sach-SW: single-photon emission
• Sach-SW: size 0.25 mm
• Sach-SW: size 1.0 mm to 5.0 mm
• Sach-SW: size 1.5 mm
• Sach-SW: size 1.51 mm
• Sach-SW: size 1.68 mm
• Sach-SW: Spatial resolution
• Sach-SW: spherical lesions
• Sach-SW: Three-dimensional displays
• Sach-SW: xyz-directions
• K10plus-PPN: 1699798214

Abstract

Aim: A method to determine the point spread function (PSF) of an imaging system based on a set of 3-D Gaussian functions is presented for a robust estimation of the recovery corrections for accurate activity quantification in positron emission tomography (PET) and single-photon emission computed tomography systems. Materials and Methods: The spatial resolution of the ALBIRA II PET subsystem was determined using a 370-kBq 22Na point source. The measured data were reconstructed with a maximum-likelihood expectation-maximization algorithm. The PSF was calculated based on the National Electrical Manufacturing Association (NEMA) NU4 2008 protocol and on alternative methods based on three 3-D fitting functions for the xyz-directions: 1) a 3-D Gaussian function (3-D 1-Gauss) and convolutions of this function with a pixel size (3-D Gaussp) or source dimension of Ø 0.25 mm (3-D Gausss); 2) the sum of two Gaussian functions (3-D 2-Gauss); and 3) three Gaussian functions (3-D 3-Gauss). Goodness of fit and the method based on an Akaike information criterion were used for choosing the best function. A MATLAB-based mathematical source simulation study was performed to quantify the relevance of PSFs calculated from the different methods. Results: Based on the PSFs calculated from the NEMA protocol, the full-width at half-maximum (FWHM) in xyz-directions were 1.68, 1.51, and 1.50 mm. The corresponding results using 3-D Gauss and 3-D Gausss functions both were (1.87 ± 0.01), (1.70 ± 0.01), and (1.50 ± 0.01) mm and for 3-D Gauss,, were (1.84 ± 0.01), (1.67 ± 0.01), and (1.47 ± 0.01) mm. The FWHMs calculated with 3-D 2-Gauss and 3-D 3-Gauss were (1.78 ± 0.01), (1.74 ± 0.01), and (1.83 ± 0.01) mm and (1.76 ± 0.03), (1.72 ± 0.03), and (1.78 ± 0.03) mm, respectively. All coefficients of variations of the fit parameters were ≤29% and the adjusted R2 were ≥0.99. Based on Akaike weights wi, the 3-D 3-Gauss method was best supported by the data (wi = 100%). The simulation study showed a relative error in quantification of spherical lesions in the range of 15%-45% for lesions of diameters 1-5 mm compared to the PSFs based on the NEMA method. Conclusion: An alternative method to calculate the PSFs of imaging systems to accurately correct for recovery effects is presented. The proposed method includes choosing and fitting of 3-D functions, validation of fitting quality, and choosing the function best supported by the data along with an estimation of the uncertainty.