A comparison of radiographic methods of diagnosing constrictive lesions of the spinal canal. Toshiba unit vs. CT scanner.

With the advent of computerized tomography (CT), a new method of visualizing the spinal canal in cross-section has been created. Before the introduction of CT scanning, evaluation of the cross-sectional anatomy of the spinal canal was accomplished chiefly by the Toshiba unit. This study compares these two forms of tomography and discusses their relative effectiveness in diagnosing constrictive lesions of the spinal canal.

Transverse axial tomography of the spine.

Transerse axial tomography is a technique by which the spine is viewed radiographically in cross section. The tomographic apparatus, technique of examination, and radiation exposure will be discussed. Examples of normal and pathologic anatomy of the cervical, thoracic, and lumbar spine will be presented. In the lumbar spine cross-sectional views of stenotic canals due to facetal hypertrophy, congenital stenosis, spondylolithesis, and ventral overgrowth of spine fusions will be demonstrated. Measurements of the sagittal and interpedicular distances on conventional x-rays have correlated poorly with the anatomic state in lumbar stenosis. A high degree of correlation has been demonstrated by plotting the cross-sectional area configuration of the bony canal, as well as a new measurement, the interfacet distance, on axial tomograms. Transverse axial tomography is an exciting, new approach in neuroradiology for the evaluation of spinal disorders which have primarily axial distortion.

Lumbar spinal stenosis. Radiographic diagnosis with special reference to transverse axial tomography.

Spinal stenosis due to malalignment and/or hypertrophy of the bony margins of the spinal canal is a recognized cause of cauda equina compression and nerve root entrapment. The plain lumbosacral spine roentgenograms reveal the number of lumbar vertebrae, their alignment, their interpedicular distances, the height of the intervertebral disk spaces and the presence of osteophyte formation. It correlates poorly with encroachment on the spinal canal. The transverse axial tomogram directly demonstrates a cross-section of the spinal canal and will show abnormal areas of bone encroachment usually arising from hypertrophied lamina and articular processes. These narrow the posterior portion of the spinal canal and encroach on the lateral recesses. This examination does not demonstrate soft tissue hypertrophy and the stenosis may be even greater than what is apparent due to the bony encroachment. The myelogram expresses how the narrowed spinal canal affects the dural sac and its contained cauda equina. Not infrequently there is an associated herniated disk.

Transverse axial tomography of the spine. Part 1: axial anatomy of the normal lumbar spine.

The authors describe the technique of transverse axial tomography of the spine and give a detailed description of the axial anatomy of the normal lumbar spine from L-4 to the sacrum. They demonstrate a specific repetitive pattern of intraosseous and articular segments, and stress the importance of the articular processes in shaping the vertebral canal and the intervertebral foramina. The authors believe axial tomography to be a simple, noninvasive radiological technique that allows cross-sectional visualization of the vertebral canal and articular processes in the living patient.

Schizencephaly: a clinical study and review.

Schizencephaly is a rare malformation in which symmetrical portions of the cerebral mantle fail to develop. It should be differentiated by angiography and pneumography from the porencephalies that follow destructive lesions and from the prognostically more favorable subdural hematomas and effusions. If the diagnosis of this anomaly can be firmly established short of surgical exploration, operation or further treatment of any kind is not, in the authors opinion, warranted.