The goal of this project is to improve the size, robustness, patient throughput and image quality of Computed Radiography systems. Operational efficiencies are increasingly driving the industry toward digital imaging. Computed radiography equipment is generally less expensive than digital radiography systems, but is perceived as offering somewhat lower image quality, and a lower patient throughput. Our technology would provide a more compact and robust system that would address the mobile market, as well as enable computed radiography to compete more effectively on an image quality and throughput basis, while maintaining its cost advantage in terms of capital expense. We propose to apply a technology that has recently become available, i.e. Vertical Cavity Surface Emitting Laser (VCSEL) arrays in the laser scanning source. VCSEL arrays can be fabricated monolithically on a single chip with a very precise spacing and good performance uniformity. The array can replace the flying spot scanners which use a single laser and a rotating mirror. This will result in a more compact and more robust scanner. In addition, the technology enables a linescan mode of operation. This ability shifts the normal trade-offs between scan speed and image quality to a more favorable point. Such linescan units have been demonstrated with discrete lasers, but the manufacturing of such systems is challenging. Our Phase I project demonstrate the feasibility of this approach by building a 2.5cm scanner which included the VCSEL array, driver I.C.s and lensing on a board, and demonstrated the ability to resolve 5 line pairs per millimeter. This proposed Phase II project will build two full width (35cm) scanners, the first with a 1005m laser pitch, and the second with a 505m laser pitch. Both prototypes will be integrated into and evaluated in real CR systems. Performance will be evaluated in terms of MTF, NPS, and DQE, and performance comparable to, and subsequently better than, existing systems will be demonstrated.
This project develops a new stimulating laser scanning technology for computed radiography which will result in a compact, robust unit with improved efficiency and image quality. A successful project would result in a cost-effective alternative for digital imaging, while maintaining high image quality. The technology is expected to be particularly beneficial to portable units, to be used bedside, in clinics, or even transported to skilled nursing facilities, and to improving the operational efficiency by dramatically improving scan and digitization times.
