A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT.

Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification.

Modeling the performance of a photon counting x-ray detector for CT: energy response and pulse pileup effects.

Purpose: Recently, photon counting x-ray detectors (PCXDs) with energy discrimination capabilities have been developed for potential use in clinical computed tomography (CT) scanners. These PCXDs have great potential to improve the quality of CT images due to the absence of electronic noise and weights applied to the counts and the additional spectral information. With high count rates encountered in clinical CT, however, coincident photons are recorded as one event with a higher or lower energy due to the finite speed of the PCXD.

Polycrystalline Mercuric Iodide Films on CMOS Readout Arrays.

We have created high-resolution x-ray imaging devices using polycrystalline mercuric iodide (HgI(2)) films grown directly onto CMOS readout chips using a thermal vapor transport process. Images from prototype 400x400 pixel HgI(2)-coated CMOS readout chips are presented, where the pixel grid is 30 mum x 30 mum. The devices exhibited sensitivity of 6.

Photon Counting Energy Dispersive Detector Arrays for X-ray Imaging.

The development of an innovative detector technology for photon-counting in X-ray imaging is reported. This new generation of detectors, based on pixellated cadmium telluride (CdTe) and cadmium zinc telluride (CZT) detector arrays electrically connected to application specific integrated circuits (ASICs) for readout, will produce fast and highly efficient photon-counting and energy-dispersive X-ray imaging. There are a number of applications that can greatly benefit from these novel imagers including mammography, planar radiography, and computed tomography (CT).