Abstract: Means for locating accurately without ambiguity tomodensitometric sections sloping in any way with respect to an original predetermined plane. At least one locating element is disposed on the part to be examined by conventional tomodensitometry, this element having a baseline situated in the original plane and having at least one characteristic such as density, varying continuously or substantially continuously along a direction perpendicular to this baseline, the variation of this characteristic being measurable on the tomodensitometric images of the different sections; this characteristic may be in particular a dimension of the element: width perpendicular to the direction perpendicular to the base in the case where the element is a triangle.

Abstract: A scanning device for axial transverse tomography comprising a single motor mounted on a first mobile support, which is rotatably mounted on a fixed base, and coupled, on the one hand, to a first indexing mechanism driving a sprocket or pinion, which engages with geared structure or chain secured to the fixed base in order to intermittently rotate the first support about a horizontal axis and, on the other hand, to a second mechanism converting a continuous rotational motion into a rectilinear reciprocating motion of a second mobile support relative to the first one, and which carries the X-ray source and detector assembly.