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Chrysoula Vraka
Dr.rer.nat. Chrysoula Vraka, MScPostdoctoral researcher (senior postdoc)

Department of Biomedical Imaging and Image-guided Therapy (Division of Nuclear Medicine)
Position: Research Associate (Postdoc)

ORCID: 0000-0003-2065-6093
T +43 1 40400 58720

Further Information


Drug Evaluation, Preclinical; Molecular Imaging; Neurosciences; Positron-Emission Tomography; Radioactive Tracers

Research group(s)

Research interests

My main research focus was to understand the pharmacokinetic properties of radiotracers and drugs in order to accelerate and improve the process of drug development in neuroscience and cancer. Several radiotracers failed in later stages of drug development caused to poor blood brain barrier (BBB) penetration or interactions to efflux transporters (drug resistance), thus predictive DMPK (drug metabolism and pharmacokinetics) assessments gain in value to determine the most promising radiotracers before conducting animal experiments. Furthermore, my academic work include radio-metabolite analysis in vivo, ex vivo for kinetic modeling in human and animal studies.

With this background, the future work will encompass whole body tracer pharmacokinetics and imaging with special focus on organ axes. Currently, I am working on mouse stress models and establishing PET imaging as a robust method for measuring stress and studying the stress response using metabolic imaging.

Techniques, methods & infrastructure

  • Radiolabeling (PET, SPECT, Therapeutics)
  • Drug development: in vitro techniques as lipophilicity, permeability, plasma protein binding, drug distribution and metabolism, cell culture (co-culture models and real-time kinetic assays), binding studies, autoradiography and ex vivo & in vitro metabolism and biodistribution studies.
  • In vivo radio-metabolite analysis for kinetic modeling (human studies)
  • Preclinical Imaging µPET/µCT
  • Metabolic Imaging
  • Cancer Imaging
  • Neuro Imaging
  • Imaging Organ-Axis/Organ-Crosstalk
  • Stress Mouse Models

Selected publications

  1. Vraka, C. et al., 2017. Log P , a yesterday’s value? Nuclear Medicine and Biology, 50, pp.1–10. Available at:
  2. Vraka, C. et al., 2018. Expanding LogP: Present possibilities. Nuclear Medicine and Biology, 58, pp.20-32. Available at:
  3. Vraka, C. et al., 2018. A new method measuring the interaction of radiotracers with the human P-glycoprotein (P-gp) transporter. Nuclear Medicine and Biology, 60, pp.29-36. Available at:
  4. Vraka, C. et al. (2022) ‘Simultaneous radiomethylation of [11C]harmine and [11C]DASB and kinetic modeling approach for serotonergic brain imaging in the same individual’, Scientific Reports, 12(1). Available at:
  5. Rischka, L. and Vraka, C. et al. (2021) ‘First-in-Humans Brain PET Imaging of the GluN2B-Containing N-methyl-d-aspartate Receptor with (R)-11C-Me-NB1’, Journal of Nuclear Medicine, 63(6), pp. 936–941. Available at: