Derivation of attenuation map for attenuation correction of PET data in the presence of nanoparticulate contrast agents using spectral CT imaging

Hossein Ghadiri, Mohammad Bagher Shiran, Hamid Soltanian-Zadeh, Arman Rahmim, Habib Zaidi, Mohammad Reza Ay

Research output: Contribution to journalArticle


Objective: Uptake value in quantitative PET imaging is biased due to the presence of CT contrast agents when using CT-based attenuation correction. Our aim was to examine spectral CT imaging to suppress inaccuracy of 511 keV attenuation map in the presence of multiple nanoparticulate contrast agents. Methods: Using a simulation study we examined an image-based K-edge ratio method, in which two images acquired from energy windows located above and below the K-edge energy are divided by one another, to identify the exact location of all contrast agents. Multiple computerized phantom studies were conducted using a variety of NP contrast agents with different concentrations. The performance of the proposed methodology was compared to conventional single-kVp and dual-kVp methods using wide range of contrast agents with varying concentrations. Results: The results demonstrate that both single-kVp and dual-kVp energy mapping approaches produce inaccurate attenuation maps at 511 keV in the presence of multiple simultaneous contrast agents. In contrast, the proposed method is capable of handling multiple simultaneous contrast agents, thus allowing suppression of 511 keV attenuation map inaccuracy. Conclusion: Attenuation map produced by spectral CT clearly outperforms conventional single-kVp and dual-kVp approaches in the generation of accurate attenuation maps in the presence of multiple contrast agents.

Original languageEnglish (US)
Pages (from-to)559-570
Number of pages12
JournalAnnals of Nuclear Medicine
Issue number6
StatePublished - Jul 2014



  • K-edge imaging
  • Multi-energy spectral CT
  • Nanoparticulate contrast agents
  • PET/CT

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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