Making X-ray imaging faster!

X-ray computed tomography is a versatile technique for 3D structure characterization, and the pursuit of a faster yet reliable scan is never ended. A lot of methods, such as the maximum likelihood expectation maximization (MLEM) and maximum-a-posteriori (MAP), have been proposed and developed to improve the speed, but most of they are mainly for the "step-scan" mode. At synchrotron facilities such as the FXI beamline at Brookhaven National Laboratory, data is normally collected in the high-speed "fly-scan" mode, which inevitably results in a blurred image using traditional reconstruction algorithms. Figure 1 illustrates how a "fly-scan" mode can introduce artifacts due to the nature of rotation. MLEM and MAP TV methods can be employed on top of the FBP reconstruction algorithm, however, their performance is still limited (see Figure 3).