Experimental evaluation of a micron-resolution CT detector

Rickard Brunskog; Mats Persson; Zihui Jin; Mats Danielsson

doi:10.1117/12.2692858

1 April 2024 Experimental evaluation of a micron-resolution CT detector

Rickard Brunskog, Mats Persson, Zihui Jin, Mats Danielsson

Proceedings Volume 12925, Medical Imaging 2024: Physics of Medical Imaging; 129250B (2024) https://doi.org/10.1117/12.2692858
Event: SPIE Medical Imaging, 2024, San Diego, California, United States

Abstract

Current photon-counting detectors are limited to a pixel size of 0.3mm to 1mm, as decreasing the pixel size further generally introduces degraded dose efficiency and energy resolution from excessive charge sharing. In this work, we present experimental measurements of the first photon-counting detector prototype designed to leverage the charge sharing to estimate the photon interaction position, where simulations indicate a theoretical resolution of around 1μm using a similar geometry. The goal of the measurements is to validate our Monte-Carlo simulation for further development. DAC sweeps are performed with an x-ray beam at specified locations on the sensor front, with the beam at 20keV and 35keV, as well as with different sensor biases with the beam at 35keV. The experimental data are then compared to a Monte Carlo simulation combined with a charge transport model. In this first prototype wire bonds are used, and as such only a few channels are connected. The experimental data agree generally well with the simulated data with the beam close to the electrodes, with the simulated data diverging from the experiments with the beam further away from the electrodes. The induced charge cloud signal exhibits a fairly linear dependency on the beam position, indicating that any estimation techniques will yield more precise position when the photon interacts further away from the electrodes, rather than closer. With the experimental data and the simulations agreeing generally well, together with the same software previously indicating a resolution of around 1μm, we expect an ultra-high-resolution detector to be in reach, and are encouraged to continue development.

Conference Presentation

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Rickard Brunskog, Mats Persson, Zihui Jin, and Mats Danielsson "Experimental evaluation of a micron-resolution CT detector", Proc. SPIE 12925, Medical Imaging 2024: Physics of Medical Imaging, 129250B (1 April 2024); https://doi.org/10.1117/12.2692858

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available