TRANSVERSE DIAMETER OF CERVICAL SPINAL CORD ON PANTOPAQUE MYELOGRAPHY.

Abstract

ROSS changes in the size of the cervical spinal cord as a result of an expanding intramedullary lesion or marked atrophy usually can be recognized by simple inspection of Pantopaque myelograms. When changes are of a minor degree, however, recognition may be difficult. In such instances, knowledge of the extent of the variation in the size of the normal cervical spinal cord would be of great value. Because of technical problems, however, consistent and reproducible measurements are difficult to obtain. Porter, 2 in a study of 6g normal Pantopaque myelograms, measured the distance between the points of emergence of the nerve roots from the cord at the 4th and 6th cervical levels only. These measurements varied between a minimum of I cm. and a maximum of 1.7 cm., with an average of 1.4 cm. It is difficult to relate these figures to the total transverse diameter of the cord. Wood a described in detail the appearance of the cervical cord as seen on spot films. According to this author, the cervical spinal cord occupies the central two-thirds of the cervical subarachnoid space and the width of the spinal cord is approximately one-half the interpediculate distance except at the level of the maximum cervical enlargement at C-5, where the spinal cord occupies almost two thirds of the vertebral canal. Standards for the sagittal diameter of the cervical spinal cord on air myelography were reported by Lowman and Finkelstein) Measurements derived from conventional spot films made during cervical myelography are subject to criticism on several bases. To a limited but unknown degree, the factors of magnification vary from patient to patient and are dependent upon the particular