Radiology, Vol 146, 409-414, Copyright © 1983 by Radiological Society of North America
Spinal cord size in syringomyelia: change with position on metrizamide myelography
S Kan, AJ Fox, F Vinuela and G Debrun
Change in the anteroposterior diameter of the cervical spinal cord was
demonstrated on metrizamide myelography in 20 out of 40 cases of cervical
syringomyelia. Twelve of these were normal-sized cords, four were small,
and four enlarged. Comparable lateral cervical myelograms in the prone and
supine positions were sufficient to show size change for normal-sized or
small cords. Additional myelograms in the erect and Trendelenburg positions
were necessary to show size change in enlarged cervical cords, especially
with associated Chiari malformation. A localized change in cord size
suggests syringomyelia. If the change in cord size is diffuse, then change
less than 10% is not necessarily significant. In undiagnosed myelopathy,
metrizamide myelography has the potential to detect unsuspected
syringomyelia even when the cord is normal-sized or small. Myelographic
study may also be useful as an adjunct to delayed computed tomographic
studies.
