Radiological imaging device comprising: - a bed defining a main direction; - a load-bearing structure suitable to support said bed in a raised position defining a free chamber between said load-bearing structure and said bed; - a gantry suitable to perform radiological imaging and defining a circular trajectory of expansion lying on a positioning plane; said gantry comprising a source able to emit a radiation; a detector able to receive the radiation after it has traversed said bed; and a casing suitable internally to house at least said source, said detector - a rotation mechanism suitable to rotate said gantry in relation to said bed and to said load-bearing structure, varying the inclination of said positioning plane in relation to said main direction; wherein - said casing comprises a static arched module connected to said rotation mechanism; at least one mobile arched module (35c, 35d); and at least one kinematic expansion mechanism able to move said at least one mobile arched module (35c, 35d) with respect to said static arched module along said circular trajectory of expansion; and in that said radiological imaging device defines a rest configuration in which said positioning plane is parallel to said main direction and wherein said at least one mobile arched module (35c, 35d) is substantially totally overlapped to said static arched module so that the angular extension of said casing is substantially equal to the angular extension of said static arched module; and at least one working configuration wherein said positioning plane is transverse to said main direction and wherein said at least one mobile arched module (35c, 35d) at least partially protrudes from said static arched module so that the angular extension of said casing is substantially higher to the angular extension of said static arched module. - a bed defining a main direction; - a load-bearing structure suitable to support said bed in a raised position defining a free chamber between said load-bearing structure and said bed; - a gantry suitable to perform radiological imaging and defining a circular trajectory of expansion lying on a positioning plane; said gantry comprising a source able to emit a radiation; a detector able to receive the radiation after it has traversed said bed; and a casing suitable internally to house at least said source, said detector - a rotation mechanism suitable to rotate said gantry in relation to said bed and to said load-bearing structure, varying the inclination of said positioning plane in relation to said main direction; wherein - said casing comprises a static arched module connected to said rotation mechanism; at least one mobile arched module (35c, 35d); and at least one kinematic expansion mechanism able to move said at least one mobile arched module (35c, 35d) with respect to said static arched module along said circular trajectory of expansion; and in that said radiological imaging device defines a rest configuration in which said positioning plane is parallel to said main direction and wherein said at least one mobile arched module (35c, 35d) is substantially totally overlapped to said static arched module so that the angular extension of said casing is substantially equal to the angular extension of said static arched module; and at least one working configuration wherein said positioning plane is transverse to said main direction and wherein said at least one mobile arched module (35c, 35d) at least partially protrudes from said static arched module so that the angular extension of said casing is substantially higher to the angular extension of said static arched module.