Low-Dose High-Resolution Dental Radiography

DESCRIPTION (provided by applicant): We are developing a high-resolution, low-dose, direct-conversion x-ray detector for intraoral Dental radiography. The detector will improve intraoral Dental imaging with reduced dose, high resolution, and low detector cost. It can be incorporated into existing Dental radiography equipment, replacing film-based or scintillator-based systems. The dose efficiency of current scintillator-CCD or - CMOS photodiode array x-ray detectors is compromised by inefficient conversion of x-rays to light, transport of the light to the detector, and conversion of the light to electric signal. We have successfully developed a new direct x-ray converter material, polycrystalline mercuric iodide, which is a high-Z large-band-gap compound semiconductor with outstanding charge collection properties. The proposed detector is a thin film of polycrystalline mercuric iodide for direct conversion of incident x-rays into charge, coupled to a CMOS readout structure for charge readout. Dose reduction will be achieved due to the very high sensitivity of mercuric iodide films. We expect to widely market the device as an OEM component to Dental radiography manufacturers. In Phase I of the project, we adapt our existing specialized high-speed large-area CMOS readout chip, specially designed for compatibility with HgI2, to the intraoral Dental application. We will measure the performance of the prototype device. In Phase II we will customize the packaging of the CMOS readout chip with a thin motherboard and ADCs arranged into a vertical stack, modify the HgI2 deposition as required for the Dental imaging application, and complete and test a full product prototype. The product we will develop will help Dentists detect hairline cracks and other high-resolution features while patients will benefit from a reduced lifetime x-ray dose.