Figure 6. Ultra-low-dose CT colonography: traditional filtered back-projection (FBP) versus novel iterative reconstruction.
3D endoluminal image from ultra-low-dose CTC series (0.3 mSv) with FBP (A) shows substantial image noise that partially obscures an 8-mm polyp (arrow). When the same CTC series is reconstructed with a novel iterative method (B), the noise is greatly reduced and the polyp (arrow) is more conspicuous. Sub-mSv 3D CTC is feasible with these newer algorithms.