Since its presentation by G.N. Hounsfield at the second Congress of the European Association of Radiology in Amsterdam in June 1971, "Computerised Trans- verse Axial Tomography" which became later on "Computerised Axial Tomography (CAT)" then simply "Computed Tomography (CT)" has developed extremely rapidly. Many papers have appeared in a short time, pointed out the substantial advantages of this new technique and precisely describing the characteristic...