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Michael Ljungberg

Michael Ljungberg

Professor

Michael Ljungberg

Improved scatter correction with factor analysis for planar and SPECT imaging

Författare

  • Peter Knoll
  • Arman Rahmim
  • Selma Gültekin
  • Martin Šámal
  • Michael Ljungberg
  • Siroos Mirzaei
  • Paul Segars
  • Boguslaw Szczupak

Summary, in English

Quantitative nuclear medicine imaging is an increasingly important frontier. In order to achieve quantitative imaging, various interactions of photons with matter have to be modeled and compensated. Although correction for photon attenuation has been addressed by including x-ray CT scans (accurate), correction for Compton scatter remains an open issue. The inclusion of scattered photons within the energy window used for planar or SPECT data acquisition decreases the contrast of the image. While a number of methods for scatter correction have been proposed in the past, in this work, we propose and assess a novel, user-independent framework applying factor analysis (FA). Extensive Monte Carlo simulations for planar and tomographic imaging were performed using the SIMIND software. Furthermore, planar acquisition of two Petri dishes filled with 99mTc solutions and a Jaszczak phantom study (Data Spectrum Corporation, Durham, NC, USA) using a dual head gamma camera were performed. In order to use FA for scatter correction, we subdivided the applied energy window into a number of sub-windows, serving as input data. FA results in two factor images (photo-peak, scatter) and two corresponding factor curves (energy spectra). Planar and tomographic Jaszczak phantom gamma camera measurements were recorded. The tomographic data (simulations and measurements) were processed for each angular position resulting in a photo-peak and a scatter data set. The reconstructed transaxial slices of the Jaszczak phantom were quantified using an ImageJ plugin. The data obtained by FA showed good agreement with the energy spectra, photo-peak, and scatter images obtained in all Monte Carlo simulated data sets. For comparison, the standard dual-energy window (DEW) approach was additionally applied for scatter correction. FA in comparison with the DEW method results in significant improvements in image accuracy for both planar and tomographic data sets. FA can be used as a user-independent approach for scatter correction in nuclear medicine.

Avdelning/ar

  • Medicinsk strålningsfysik, Lund

Publiceringsår

2017-09-01

Språk

Engelska

Publikation/Tidskrift/Serie

Review of Scientific Instruments

Volym

88

Issue

9

Dokumenttyp

Artikel i tidskrift

Förlag

American Institute of Physics (AIP)

Ämne

  • Radiology, Nuclear Medicine and Medical Imaging
  • Other Physics Topics

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0034-6748