Patent ID: 6845141

Claim:
A computed tomography apparatus comprising: a radiation source which emits a radiation beam from a focus, said radiation beam having a fan angle and at least said focus being displaceable relative to a system axis to irradiate a measuring field, defined by said fan angle, from a plurality of different directions for scanning an object adapted to be located in said measuring field and to at least partially irradiate a portion of said object disposed beyond said measuring field; a radiation detector on which said radiation beam is incident after passing through said measuring field and said portion of said object disposed beyond said measuring field, said radiation detector generating output electrical signals corresponding to radiation in said radiation beam incident on said radiation detector; and a computer connected to said radiation detector and supplied with said electrical output signals, said computer reconstructing an image of said object from data represented by said electrical output signals for a reconstruction field which is larger than said measuring field, said reconstruction field including said portion of said object beyond said measuring field.