Integrated distortion correction and reconstruction technique for digital mosaic mammography

Investigations in the area of digital mammography have been limited by the resolution of the sensor devices employed. We have proposed a multiple camera or mosaic architecture in which adjacent sensors observe an overlapping field of view. Such a technique can deliver extremely high resolution while simultaneously maintaining a moderate cost for the resultant instrument. However, this technique's clinical efficacy will be limited by the ability to accurately and precisely reconstruct a single continuous image from multiple CCD sensors. We present an integrated algorithm which will correct distortions introduced by the camera while addressing the problem of image reconstruction or 're- stitching.' Such a technique will minimize pixel loss by limiting image re-sampling to a single incident. Custom designed calibration screens were employed for the calculation of camera distortion and intra-camera disparity. A parallel digital signal processor architecture has been developed to accelerate system performance when employing a large number of camera inputs. We present a quantitative evaluation of our reconstruction technique and an analysis with respect to similar methods of image reconstruction. We have previously constructed and presented a prototype imager for digital radiography based upon a similar sensor architecture. The algorithm presented will significantly enhance the feasibility of our multiple camera architecture for both digital radiography and mammography. We believe that such a methodology will enhance diagnostic accuracy at a moderate cost when compared with system of similar imaging resolution.