A radiological imaging device includes a gantry defining an analysis area configured to contain a portion of a patient to be analyzed and a circular extension trajectory extending around a central axis. The gantry includes a source configured to emit radiation; a detector configured to receive the radiation after it has passed through the analysis area; and a casing defining a housing volume for the source and the detector. The casing includes a bottom arched module and an arched module mobile with respect to the bottom arched module so as to vary the angular extension of the casing. The gantry includes a movement apparatus of the arched modules including a bottom guide integral with the bottom arched module and defining a bottom circular movement trajectory centered on the central axis; a mobile guide integral with the mobile arched module and defining a circular movement trajectory centered on the central axis; and a thrust assembly configured to engage the guides commanding the rotation of the arched modules around the central axis.