Patent ID: 8170317

Claim:
An examination apparatus for iso-centering an object of interest to be examined, the examination apparatus comprising: an X-ray acquisition unit which performs a first short acquisition for a first acquisition geometry with a focal spot in a first location, resulting in a first projection data, and which performs a second short acquisition for a second acquisition geometry with the focal spot in a second location, resulting in a second projection data; a data processor which determines a translation vector pointing from a point of gravity of the object of interest to an iso-centre of the examination apparatus, the data processor being programmed to: segment the object of interest in the first projection data; segment the object of interest in the second projection data; determine a first two-dimensional point of gravity of the segmented object of interest in the segmented first projection data automatically; determine a second two-dimensional point of gravity of the segmented object of interest in the segmented second projection data automatically; determining a first three-dimensional intersection of a first line and second line, the first line pointing from the first focal spot location to the first two-dimensional point of gravity of the segmented object of interest in the first projection data and the second line pointing from the second focal spot location to the second two-dimensional point of gravity of the segmented object of interest in the second projection data, the first three-dimensional intersection being a point of gravity of the segmented object of interest; determine a second three dimensional intersection of a third line and a fourth line, the third line pointing from the first focal spot location to a first mid-point of the first projection data and the fourth line pointing from the second focal spot location to a second mid-point of the second projection data, the second three-dimensional intersection being an iso-centre of the examination apparatus; determine a translation vector pointing from the point of gravity of the segmented object of interest to the iso-centre of the examination apparatus; transform the translation vector into a table coordinate system, the table coordinate system corresponding to a degrees of freedom of a movable table unit on which the object of interest is supported; and control the movable support unit to automatically iso-center the object of interest by shifting the movable table unit based on the translation vector.