Semiconductor detector for low-dose, high-resolution dental DR imaging

Research and Related Other Project Information – Project Summary/Abstract Dental caries is a persistent public health problem that impacts a large fraction of the US population. Nearly all adults in the United States are considered at risk of developing tooth decay, and for children it is a common chronic disease. Though widely and routinely used, there are always concerns about patient exposure to X-rays during radiographic imaging – a concern especially heightened with children. Radiation Monitoring Devices (RMD) proposes to develop an improved digital X-ray detector for dental radiography that will retain all the benefits of a current digital technology, while improving sensitivity and reducing patient dose. The device will involve the integration of two technologies - silicon based imaging arrays and semiconductor x-ray conversion layers. The silicon capabilities are well understood, with CCD and CMOS devices well established in dental imaging. The application of a semiconductor conversion layer is the more innovative and challenging aspect of the concept. RMD's innovation is to replace the commonly used CsI or amorphous selenium X-ray receptors with the semiconductor thallium bromide (TlBr). TlBr will provide a much greater dose efficiency and higher image contrast. The advantage to dental imaging is that dentists will get the high resolution images that they are accustomed to, but now with a much lower dose to the patient. During Phase I, RMD will develop the processes to fabricate high quality films of TlBr and compare the technology to existing detector films to demonstrate the superiority of TlBr. The work plan will encompass film deposition, investigation of compatible electrode layers to work in conjunction with the TlBr, identification and mitigation strategies of technical challenges that arise, and completion of a wide range of electrical and physical tests to gauge X-ray sensitivity and image quality. In Phase II RMD will optimize the processes, fabricate X-ray imaging detectors on KA Imaging CMOS ROICs and fully characterize a complete detector system. The result of this research will be a new digital radiography detector with comparable or better image quality and significantly lower patient dose than currently used detectors.