What are the reconstruction steps for helical scan tomography of 3D function f(x,y,z) assuming z is sampled at nyquist rate 1/dz so that slices f(x,y,k*dz) can be defined.
Getting projections as
P (t) = $ \int f(tcos(\theta) - rsin(\theta), tcos(\theta) + rsin(\theta), \theta /dz) dr $
Is this for CT? Is the imaging device a plane (cone beam tomography)? If so, there's a helical back projection algorithm, but I think you'll have to read about it in a book; it's a bit involved. Basically, you do a filtered back projection for each slice like in regular CT.
It's not a perfect reconstruction.
