# MedTechLabs Seminar: Photon-counting CT reconstruction with a deep-learning-based physics model

This thesis is a first step towards showing that deep learning model corrections are a viable way of accelerating the reconstruction process in Photon-Counting CT

**Time: **
Thu 2021-06-17 16.00

**Location: **
Online

**Lecturer: **
Emanuel Ström, KTH

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**Abstract**

Photon-Counting CT is a rapidly developing alternative to conventional CT that promises higher spatial resolution, more accurate material separation and more robust reconstructions. A challenge when developing Photon-Counting CT image reconstruction methods is accounting for nonidealities in the image acquisition, such as cross-talk between detector pixels, which can generate artifacts if not corrected for. In this thesis, we accelerate image reconstruction tasks for photon-counting CT by approximating the cross-talk component of the forward operator with a deep neural network, resulting in a learned forward operator. The learned operator reduces reconstruction error by an order of magnitude at the cost of a 20% increase in computation time, compared to ignoring cross-talk altogether. Furthermore, it generalises well to both unseen data and unseen detector settings. This thesis is a first step towards showing that deep learning model corrections are a viable way of accelerating the reconstruction process in Photon-Counting CT.

**Emanuael Ström, KTH, **presents his master thesis **"**Learning the Forward Operator in Photon-Counting Computed Tomograph"