[The spinal canal, dural sac and spinal cord on cervical myelograms. Possibilities of quantification using a computer].

The objective of the presented work was to investigate anatomical structures of the cervial spine and their interrelations on cervical myelograms in a neutral position and in retroflexion. Cervical myelograms were made in 34 patients from a lateral approach between the first and second vertebra. In a neutral position and in retroflexion the relations of the dural sac and spinal canal were investigated in 26 subjects with a normal antero-posterior diameter of the spinal canal and in eight patients with congenital stenosis of the spinal canal. Quantification by means of a computer revealed that in retroflexion the antero-posterior diameters of the dural sac diminishes significantly in subjects with a normal antero-posterior diameter of the spinal canal as well as in subjects with congenital stenosis of the spinal canal. Moreover, the authors provided evidence that the area of the dural sac diminishes significantly in retroflexion, as compared with the neutral position in subjects with a normal spinal canal as well as in subjects with congenital stenosis of the spinal canal.