The value of computed tomographic metrizamide myelography in the neuroradiological evaluation of the spine.

Abstract

The diagnostic value of plain film metrizamide myelography (PFMM) was compared with computed tomographic metrizamide myelography (CTMM) in a study of 106 individuals who had undergone high-resolution computed tomographic scanning of the spine. CTMM provided more significant information than PFMM in 42 of 106 cases (40%), but showed no advantage over PFMM in 63 of 106 cases (59%). In 19 of the 42 cases (45%), PFMM was useful in directing the CT analysis to the appropriate region of pathology. In one patient, PFMM revealed a mobile herniated disc that had not been visualized with CTMM. In 30 of 106 cases in which plain CT scans of the spine were also obtained, the addition of intrathecal metrizamide demonstrated additional pathology in ten individuals. In general, CTMM was useful in the delineation of a variety of pathologic entities, especially neoplasms and congenital abnormalities. Low-dose CTMM (3 ml of a 150 ml/mg concentration) was performed as an outpatient procedure and found to be a useful adjunct to plain CT in two patients. A schema for the radiological evaluation of pathology of the spine is presented.

Computed Tomography in Low Back Pain before and after Myelography

“…A postmyelography CT examination can be advantageous, but not always as helpful as expected (5). There seem to be no previous studies where conventional CT and postmyelography CT examinations have been performed on the same day, i.e.…”

“…under equal conditions in regard to the general condition of the patient and the lumbo-ischialgic pain syndrome. Earlier investigators (5) have recommended a rotation of the patient for 360 degrees prior to the postmyelography CT examination in order to prevent layering of the contrast medium. In the present study the patients were instructed to remain supine until the examinations were concluded.…”

“…Following lumbar myelography, a lumbar CT examination can be performed while the contrast medium is still present in the dural sac (1, [3][4][5]7,9,12,14). A CT examination of the dural sac and root sheaths when filled with contrast medium may give a conclusive diagnosis in cases where the myelographic findings are equivocal.…”

“…However, small lesions may remain undetected in patients with too high contrast medium concentration in the dural sac (9). Trials have been carried out both with small amounts of contrast medium alone (5), and with a delay in the CT examination of up to 6 hours after myelography when the contrast medium in the dural sac has become more diluted (11). Many patients scheduled for lumbar myelography have already had a conventional CT examination, and the myelography is indicated because of discrepancy between the clinical and the CT findings.…”

Neuroradiology Back to the Future: Spine Imaging

“…59 During the next several years, articles describing the efficacy of combining myelography with CT in a variety of pathologic conditions were published. 60 In the early 1980s, lumbar spine CT after IV contrast administration was used to aid in the diagnosis of degenerative disease, especially in the cervical spine, in the postoperative lumbar spine to differentiate recurrent disk from scar, and in tumors and inflammatory diseases of the spine. 8 Although the history of MR imaging dates back to the 1940s, the first commercial MR imaging scanner was introduced in 1980 and the first superconducting magnet was put in clinical use in 1981.…”