Design of a new multi-projection imaging system for chest radiography

Overlapping anatomical structures may confound detection of lung nodules in conventional projection chest radiography. To alleviate the visual clutter due to overlying anatomy, a dedicated digital multi-projection system for chest imaging was recently developed at the Radiology Department of Duke University. The system has a translating X-ray tube and acquires multiple projections of the same patient in rapid succession from slightly different angles about the posterior- anterior (PA) orientation. Geometric correlation information across these multiple projections is used to positively identify suspicious nodules and reduce false alarms. The unique feature of this system is that it can acquire images along both the horizontal and vertical axes and is therefore capable of traversing an arbitrary trajectory on a plane parallel to the detector. We are reporting the physical design considerations in the development of the multi-projection imaging system and the initial performance in our ongoing clinical trials using the system. Future application in correlation imaging and stereoscopic imaging are also noted.