In the present invention, an iterative process is provided for computed
tomographic fluoroscopy (CTF) based upon an ordered-subset based algorithm
or an adaptation of the row-action expectation maximization (RAEM)
formula. This process is applied to reduce metal artifacts in CTF imaging,
reduce image noise and provide rapid-image updating suitable for real-time
applications. In one embodiment, generation of a projection mask and
computation of a relaxation matrix are used to compensate for beam
divergence and data incompleteness, and a priori knowledge such as a known
image support is used to reduce image reconstruction errors.