1. A method for point reconstruction and metric measurement on radiographic images comprising the following steps: a) positioning a fluoroscope for producing a radiographic image, in a position where an operator can observe points inside a patient's body on which points at least one of: (A) reconstruction and (B) metric measurement are to be carried out; b) positioning a positioning device on said patient's body at an arbitrarily selected point F visible in a radiographic image; c) designating target points T.sup.i, being points to be reconstructed by said operator on said radiographic image; d) finding planes .pi..sup.i passing through the x-ray source and a line FT.sup.i by successively rotating said positioning device for each target point T.sup.i in first and second different arbitrary planes passing through said point F so that its image goes through an image of said target point T.sup.i ; e) rotating said fluoroscope to a new position and taking a new radiographic image from this new viewpoint; f) designating target points T.sup.i, being points to be reconstructed, by said operator on said new radiographic image; g) computing first the orientation of vectors Ft.sup.i ; h) computing the length of vectors .parallel.FT.sup.i .parallel.; i) visualizing points {T.sup.i, i=1. .. n} in a coordinate system associated to the point F; and j) computing distances .parallel.T.sup.i T.sup.j .parallel., i,j=1. .. n.