Comparative assessment of different energy mapping approaches in CT based attenuation correction: A patient study

M. Shirmohammad, Mohammad Reza Ay, S. Sarkar, A. Rahmim, H. Zaidi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Attenuation correction of PET emission data using spatially correlated CT images is fast and precise yielding a noise-free attenuation map (μmap) in comparison with radionuclide transmission scanning (TX). However, it is essential to convert the linear attenuation coefficients obtained from CT scans to those corresponding to 511 keV. Several conversion strategies have been developed including scaling, segmentation, hybrid and bilinear methods. The aim of this study is to compare the accuracy of different energy mapping methods for generation of 511 keV μmap using clinical studies. The procedure for generation of attenuation map from CT images using different energy mapping methods was assessed using clinical studies and the results compared to the TX image derived using Ga-68 rod sources acquired on the Discovery LS PET/CT scanner, were used as gold standard in this study. A region of interest analysis was performed at different locations of the μmaps. It was shown that for soft tissues, the relative difference of scaling, segmentation, hybrid and bilinear methods compared to TX technique were 11.3%, 9.2%, 11.3% and 10.8% respectively (no major difference). For bony structures, the quantitative analysis showed that the scaling method produces a substantial relative difference (31%). The relative difference of segmentation, hybrid and bilinear methods compared to TX were 29%, 14% and 18% respectively. However these results for lung tissue were 4%, 13%, 4% and 4% respectively for scaling, segmentation, hybrid and bilinear methods with a great difference for segmentation method. It can be concluded that for soft tissues all energy mapping methods give satisfactory results. For bone, the scaling and segmentation methods yield substantial relative differences but the other 2 methods give acceptable results. For lung tissue the results are approximately close to each other except for segmentation method.

Original languageEnglish (US)
Title of host publication4th European Conference of the International Federation for Medical and Biological Engineering - ECIFMBE 2008
Pages496-499
Number of pages4
DOIs
StatePublished - Dec 1 2008
Event4th European Conference of the International Federation for Medical and Biological Engineering, ECIFMBE 2008 - Antwerp, Belgium
Duration: Nov 23 2008Nov 27 2008

Publication series

NameIFMBE Proceedings
Volume22
ISSN (Print)1680-0737

Other

Other4th European Conference of the International Federation for Medical and Biological Engineering, ECIFMBE 2008
CountryBelgium
CityAntwerp
Period11/23/0811/27/08

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Keywords

  • Attenuation Correction
  • LAC
  • TX
  • μmap

ASJC Scopus subject areas

  • Bioengineering
  • Biomedical Engineering

Cite this

Shirmohammad, M., Ay, M. R., Sarkar, S., Rahmim, A., & Zaidi, H. (2008). Comparative assessment of different energy mapping approaches in CT based attenuation correction: A patient study. In 4th European Conference of the International Federation for Medical and Biological Engineering - ECIFMBE 2008 (pp. 496-499). (IFMBE Proceedings; Vol. 22). https://doi.org/10.1007/978-3-540-89208-3_118