Patent Number: 
Section: abstract

A computed tomography apparatus includes a scanning unit which is rotatable relative to an examination zone, about an axis of rotation extending through the examination zone, a radiation source for generating a radiation beam, a diaphragm arrangement which is arranged between the radiation source and the examination zone in order to form a fan beam traversing the examination zone from the radiation beam, and a two-dimensional detector arrangement including a plurality of detector elements and a part of the measuring surface of which detects primary radiation from the fan beam whereas another part of its measuring surface detects scattered radiation produced in the examination zone. Perfect acquisition of the momentum transfer spectrum is achieved in that a collimator arrangement with a plurality of lamellas is arranged between the examination zone and the detector arrangement. The lamellas preferably are situated in planes that intersect each other at the focus of the radiation source and subdivide the fan beam into a number of segments so that the detector elements present in a column extending parallel to the axis of rotation are struck by primary radiation or scattered radiation from the same segment.