Lam KS, Carlin D, Mulholland RC.
The Centre for Spinal Studies and Surgery, University Hospital,
Nottingham, United Kingdom. Disagreement still exists in the literature
as to the significance of the high-intensity zone (HIZ) demonstrated
on magnetic resonance imaging (MRI) as a potential pain indicator
in patients with low back pain. A prospective blind study was therefore
conducted to evaluate the lumbar di! sc high-intensity zone with
the pain provocation response of lumbar discography. Consecutive
patients with low back pain unresponsive to conservative treatment
and being considered for spinal fusion were subjected to MRI followed
by lumbar discography as a pre-operative assessment. The discographer
was blinded to the results of the MRI scans. We used the chi-squared
test to analyse our results. Ninety-two HIZs were identified in
73 patients, mainly occurring at L4/5 (48%) and L5/S1 (35%). Significant
correlation was found between abnormal disc morphology and the HIZ
(P < 0.001). In morphologically abnormal discs (grades 3, 4 and
5), there was a significant correlation between the HIZ and exact
or similar pain reproduction (P < 0.001). The sensitivity, specificity
and positive predictive value for pain reproduction were high, at
81%, 79% and 87% respectively. The nature of the HIZ remains unknown,
but it may represent an area of secondary inflammation as a result
of an an! nular tear. We conclude from our study that the lumbar
disc HIZ observed on MRI in patients with low back pain is likely
to represent painful internal disc disruption.
PMID: 10766075 [PubMed - indexed for MEDLINE]
