Method for acquiring a radiographic image of a patient with an apparatus comprising at least an X-ray source and at least an X-ray detector, said X-ray source and detector being supported in an opposed position, the objet under investigation being positioned in an intermediate position between said X-ray source and detector and in the propagation bundle of the radiation emitted by said X-ray source, moreover said X-ray source and detector being movable along a pre-set trajectory thanks to at least two movements:- a rotational movement of said X-ray source and detector around a rotation axis (R),- a translational movement of said axis of rotation (R) along at least a direction (Y) in the horizontal plane perpendicular to said rotation axis (R), or a rotational movement of said rotation axis (R) around a second axis of rotation perpendicular to the horizontal plane, i.e. parallel to said common rotation axis (R)while thanks to the combination of said movements, the virtual rotation centre (CVR), i.e. the instat center of rotation, of said X-ray source and detector moves during each acquisition, the method comprising:- the acquisition of a pre-exam image (scout)- the successive acquisition of the real image,for acquiring scout image, the rotation of said X-ray source and detector around the common axis of rotation (R) occurs in opposite direction with respect to the rotation direction of said X-ray source and detector around the common rotation axis (R) during the exposure for acquiring the real image.
