Tomographic imaging with nonuniform angular sampling.

A new class of polar sampling patterns for projection imaging is described. In contrast to conventional techniques, a nonuniform variation of the angular increments between consecutive projections is introduced. The proposed method allows adaptation of the polar sampling pattern to different shapes of the object. Numerical simulations and MR experiments verify that angular sampling density can be varied according to the radial extension of the object, resulting in a reduction of the total number of required projections (and X-ray exposure) compared with conventional circular field-of-view imaging.