Comparative assessment of different energy mapping methods for generation of 511-KEV attenuation map from ct images in pet/ct systems: a phantom study

M. Shirmohammad, M. R. Ay, S. Sarkar, H. Ghadiri, A. Rahmim

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

Abstract

The use of X-ray CT images for CT-based attenuation correction (CTAC) of PET data results in the decrease of overall scanning time and creates a noise-free attenuation map (μmap). The linear attenuation coefficient (LAC) measured with CT is calculated at the x-ray energy rather than at the 511 keV. It is therefore necessary to convert the linear attenuation coefficients obtained from the CT scan to those corresponding to the 511 keV. Several conversion strategies have been developed including scaling, segmentation, hybrid, bilinear and dual-energy decomposition methods. The aim of this study is to compare the accuracy of different energy mapping methods for generation of attenuation map form CT images. An in-house made polyethylene phantom with different concentrations of K2HPO4 was used in order to quantitatively measure the accuracy of the nominated methods, using quantitative analysis of created μmaps. The generated μmaps using different methods compared with theoretical values calculated using XCOM cross section library. Accurate quantitative analysis showed that for low concentrations of K2HPO4 all these methods produce acceptable attenuation maps at 511 keV, but for high concentration of K2HPO4 the last three methods produced the lowest errors (10.1% in hybrid, 9.8% in bilinear, and 4.7% in dual energy method). The results also showed that in dual energy method, combination of 80 and 140 kVps produces the least error (4.2%) compared to other combinations of kVps.

Original languageEnglish (US)
Title of host publication2008 5th IEEE International Symposium on Biomedical Imaging
Subtitle of host publicationFrom Nano to Macro, Proceedings, ISBI
Pages644-647
Number of pages4
DOIs
StatePublished - Sep 10 2008
Event2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, ISBI - Paris, France
Duration: May 14 2008May 17 2008

Publication series

Name2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Proceedings, ISBI

Other

Other2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, ISBI
CountryFrance
CityParis
Period5/14/085/17/08

Keywords

  • CTAC
  • Energy mapping
  • PET/CT
  • μMap

ASJC Scopus subject areas

  • Biomedical Engineering

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    Shirmohammad, M., Ay, M. R., Sarkar, S., Ghadiri, H., & Rahmim, A. (2008). Comparative assessment of different energy mapping methods for generation of 511-KEV attenuation map from ct images in pet/ct systems: a phantom study. In 2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Proceedings, ISBI (pp. 644-647). [4541078] (2008 5th IEEE International Symposium on Biomedical Imaging: From Nano to Macro, Proceedings, ISBI). https://doi.org/10.1109/ISBI.2008.4541078