French
English
Scientific context
The CREATIS laboratory (www.creatis.insa-lyon.com) (Lyon, France) opens a Postdoctoral Research Fellowship funded by the European H2020 project SPCCT. The core objective of this project is to develop and validate a new imaging technology combining Spectral Photon Counting Computed Tomography (SPCCT) and dedicated contrast agents to accurately detect, characterize and monitor neurovascular and cardiovascular diseases. The project is lead by Philippe Douek of the Université Claude Bernard Lyon 1. The recruited postdoc will contribute to workpackage 1 Image Acquisition, Reconstruction and post-processing lead by Philips Research (Hamburg, Germany) and Philips Medical Systems Technologies (Haifa, Israel).
Dual-energy x-ray CT [1] is becoming a widespread clinical tool thanks to the recent development of commercial scanners. K-edge imaging is going further using spectral photon counting detectors [3] to reconstruct the spatial distribution of a K-edge contrast material [2]. The prototype pre-clinical scanner reconstructs the K-edge image in a two-step process: (1) decomposition of the acquired data into a K-edge sinogram and two other materials, and (2) filtered backprojection reconstruction. Promising results have been obtained but the sensitivity still needs to be increased.
Goal and tasks
The goal of this project is to exploit the sparse nature of K-edge images in an iterative reconstruction technique to improve the sensitivity to lower concentrations of contrast materials. The postdoctoral fellow will model the pre-clinical scanner installed at CERMEP (Lyon, France) in collaboration with Philips Hamburg. He will then implement sparsity-promoting reconstruction after or during material decomposition. Finally, he will implement joint material decomposition and sparse reconstruction. The developments will have to be validated on simulated and real pre-clinical data.
Profile
- Education: The candidate must hold a PhD in medical imaging, applied mathematics or physics.
- Experience: Inverse problems, tomographic reconstruction.
- Languages: English required, French optional.
- Location: Lyon, France, with regular planned trips to Philips Research Hamburg, Germany.
- Salary (net): depending on experience, according to UCBL salary scale, starting at 1900 euros / month.
- Period: 2 years starting as soon as possible.
Contact
Send CV and a brief statement of interest by email to Simon Rit: simon.rit@creatis.insa-lyon.fr.
References
[1] R.E. Alvarez and A. Macovski. Energy-selective reconstructions in X-ray computerized tomography. Phys Med Biol, 21(5):733–744, Sep 1976.
[2] J.P. Schlomka, E. Roessl, R. Dorscheid, S. Dill, G. Martens, T. Istel, C. Ba ̈umer, C. Herrmann, R. Steadman, G. Zeitler, A. Livne, and R. Proksa. Experimental feasibility of multi-energy photon-counting K-edge imaging in pre-clinical computed tomography. Phys Med Biol, 53(15):4031–4047, Aug 2008.
[3] K. Taguchi and J.S. Iwanczyk. Vision 20/20: Single photon counting x-ray detectors in medical imaging. Med Phys, 40(10):100901, Oct 2013.