A medical computed tomography apparatus, said apparatus includes - a support construction (1) that is arranged to support a substantially ring-shaped structure (2) that supports imaging means, said imaging means includes a radiation source ( 21) and an image information receiver (22), said imaging means are disposed within said substantially ring-shaped structure (2) that supports the imaging media substantially on opposite sides of each other and movable within said structure with ring shape (2) supporting the imaging means, - said apparatus includes, in said ring-shaped structure (2) supporting the imaging means, an examination opening (4) wherein the object in which it is It is going to perform the imaging, it can be placed for the imaging, - and in said apparatus said substantially ring-shaped structure (2) that supports the imaging means It is movable with respect to said support construction (1) at least in the vertical direction and, on the other hand, rotating with respect to an axis substantially parallel with the horizontal diagonal of a radial cross-section of the structure in the form of ring (2) in question, characterized in that said substantially ring-shaped structure (2) supporting the imaging means includes an outer cover (3) whose cross section in a perpendicular direction with respect to the central axis of said shaped structure ring (2) is for its predominant part arranged substantially in the form of a circle arc but comprising a cut, and within the sector covered by the cut the distance from the center of said arc of a circle to the edge of the outer cover (3) is shorter than within said part of the outer cover (3) having substantially the shape of an arc of a circle, because said Examination berture (4) is disposed for its predominant part substantially in the form of a circle arc but to comprise an extension, and within the sector covered by the extension the distance from the center of said circle arc to the edge of the opening of examinatio
