Radiation Monitoring Devices (RMD) proposes to develop a new dental x-ray imager that will have all the advantages of a digital technology, retain the most desirable aspects of image quality that film emulsions provide, and most importantly, reduce dose to patients. The device will be a blend of two technologies ? silicon based imaging arrays and semiconductor x-ray conversion layers. The silicon capabilities are better understood, with CCD and CMOS devices well established in dental imaging. The application of a semiconductor conversion layer is the more challenging aspect, but advances being made in related medical fields (such as mammography) demonstrate the potential for extraordinary quality images. RMD wants to bring a similar technological revolution to dental imaging. The variation to the above referenced technology is to replace the current x-ray receptor (selenium) with a different semiconductor layer ? mercuric iodide (HgI2) ? that will provide greater dose efficiency and higher image contrast. Instead of a-Si TFT arrays, a CMOS passive pixel array will be adapted for the HgI2 converter layer. The advantage to dental imaging is that dentists will get the high resolution images that they are accustomed to with film, but now with a much lower dose to the patient. RMD will work on tailoring mercuric iodide detection layers to a high resolution CMOS device. The work plan will encompass making a variety of test devices and fully evaluating their physical, electrical and imaging characteristics. At the end of Phase 1, it is desired to have demonstrated a device with exceptional image potential quality that is better than conventional digital technology with phosphors and scintillators. And because of the key direct converter technology, the dose per image will be vastly reduced from current norms.
This project is to develop a new construction of dental imaging technology that can provide both high resolution and high efficiency, the latter being important to reducing radiation dose from routine x-ray examinations. The innovative sensor will also be applicable to medical disciplines such as mammography and micro computed tomography.
