1-μm spatial resolution in silicon photon-counting CT detectors

Area of Science:

• Medical Imaging
• Detector Physics
• Semiconductor Technology

Background:

• Current scintillator-based computed tomography (CT) detectors are limited by ~1 mm pixel size.
• Direct conversion photon-counting detectors show promise with ~0.3 mm resolution.

Purpose of the Study:

• To develop a deep silicon photon-counting detector for sub-0.1 mm spatial resolution.
• To evaluate the feasibility of using charge cloud shape from Compton interactions to enhance spatial resolution.

Main Methods:

• Utilized Monte Carlo photon simulation and a charge transport model.
• Simulated a deep silicon detector with 0.05 mm pixel size.
• Developed a method to estimate X-ray interaction position based on charge cloud shape.

Main Results:

• Achieved spatial resolution of 7.1 µm parallel and 3.1 µm orthogonal to the silicon wafer.
• Simulations considered electronic noise and a 0.88 keV threshold.

Conclusions:

• Presented a simulation of a deep silicon detector enabling ultra-high resolution X-ray interaction position estimation.
• High spatial resolution is crucial for detecting finer details in medical images.
• Potential for practical implementation of phase contrast imaging in CT.