Image quality in extended arc filtered digital tomosynthesis

Purpose: To study image quality in filtered digital tomosynthesis (FDTS) to mograms as a function of their reconstruction are, using isocentrically acq uired, fluoroscopic projection data. Material and Methods: Both digital tomosynthesis (DTS) and cone beam CT (CB CT) reconstruction algorithms are based on backprojection and use cone beam projection data as input. Under limited angle conditions, CBCT is reduced to FDTS, where only a subset of projection data are used for reconstruction . The effect of the reconstruction are on the spatial resolution, slice thi ckness, contrast sensitivity, shape distortion and artifacts, was also expe rimentally studied. The investigation was performed using both simulated an d actual fluoroscopic images. Results and Conclusion: Image quality in terms of spatial resolution, slice thickness, shape distortion and artifacts, improved with increasing recons truction are and was optimized at 180 degrees, while contrast continued to improve as the are was increased to 360 degrees. However, DTS was determine d to be the technique of choice when reconstruction arcs of less than 40 de grees were used. Consequently, FDTS may be successfully implemented in appl ications involving extended are reconstructions, in the range between 40 de grees delimiting the DTS domain and 360 degrees corresponding to CBCT.