Step 1.
Get a list of all the files. This can be done with SetDirectory and FileNames:
SetDirectory["D:\\GROUP\\PERSONAL FILES\\CHIH LIN\\output"]
files = FileNames[];
Step 2.
Apply your functions to the image. There are many different ways of doing this. It can be done efficiently with Map or ParallelMap:
slices = Map[Composition[InverseRadon,Image,Import], files];
Step 3.
Put the images together:
Image3D[slices]
