H. Komori et al., CONTRAST-ENHANCED MAGNETIC-RESONANCE-IMAGING IN CONSERVATIVE MANAGEMENT OF LUMBAR DISC HERNIATION, Spine (Philadelphia, Pa. 1976), 23(1), 1998, pp. 67-73
Study Design. This study was designed to investigate the morphologic c
hanges in contrast-enhanced magnetic resonance imaging that occur duri
ng conservative treatment of patients with unilateral leg pain resulti
ng from herniated nucleus pulposus without significant lumbar canal st
enosis. Objectives. To compare the morphologic results with clinical o
utcomes to ascertain whether enhanced magnetic resonance imaging contr
ibutes to the management of lumbar disc herniation. Summary of Backgro
und Data. Contrast-enhanced magnetic resonance imaging has already bee
n reported to be useful in the postoperative examination of the lumbar
spine and in visualization of symptomatic nerve roots. However, there
have been few reports about its usefulness in the conservative manage
ment of herniated nucleus pulposus or about the correlation between he
rniated nucleus pulposus regression and enhanced effect. The study pop
ulation consisted of 48 patients with radiculopathy. All patients prim
arily reported unilateral leg pain, and 94% had positive tension signs
. Additionally, 38% exhibited muscle weakness corresponding to the sym
ptomatic nerve root. Methods. All patients were studied twice or more
using gadolinium-magnetic resonance imaging during conservative therap
y, at a mean interval of 191 days. Changes in the size of the herniate
d nucleus pulposus on precontrast images fell into four categories, wi
th changes in enhancement on postcontrast images classified into two c
ategories: ''enlargement'' and ''no change.'' Results. In all cases of
migrating type herniated nucleus pulposus, circular enhancement was s
een on postcontrast images. In 17 of 22 cases, the enhanced area gradu
ally thickened and intruded into the migrated disc materials as the si
ze of the herniated nucleus pulposus decreased; the herniated nucleus
pulposus disappeared in nine cases and showed a marked decrease in sev
en cases. These cases showed good clinical courses of sciatica. In the
other five patients, in whom there were no changes in the enhanced ar
ea, there was less of a tendency for the herniated nucleus pulposus to
decrease in size, and there were poorer clinical results. In six case
s of extruding-type herniated nucleus pulposus, no enhanced effects we
re observed throughout the follow-up period. The other 20 cases showed
enhancement that was relatively weaker than that of migrating disc he
rniation. Extension or expansion of the enhanced area was observed in
the follow-up images of 15 cases, though only four showed obvious chan
ges in the size of the herniated nucleus pulposus. These 15 cases had
better clinical results than the other cases, in which enhanced effect
s did not change or were not observed. Conclusion. Contrast-enhanced m
agnetic resonance imaging is a useful prognostic parameter, and multip
le use contributes to the proper management of lumbar disc herniation.