Brucellar spondylodiscitis: magnetic resonance imaging features with conventional sequences and diffusion-weighted imaging.

PURPOSE: In this retrospective study, we evaluated the contribution and role of diffusion-weighted imaging (DWI) in differentiating acute and chronic forms of brucellar spondylodiscitis. We also describe the characteristics and some indistinguishable features of brucellar spondylodiscitis on magnetic resonance imaging (MRI) to emphasise the importance and limitations of MRI.

MATERIALS AND METHODS: MRI examinations of 25 patients with brucellar spondylodiscitis were retrospectively reviewed and analysed by two experienced radiologists. Signal and morphological changes were assessed. The imaging characteristics of acute and chronic forms of spondylodiscitis were compared. Both discriminative imaging findings of brucellar spondylodiscitis and some uncommon findings were interpreted.

RESULTS: Of 25 patients with spinal brucellosis, eight had thoracic, ten had lumbar, five had both thoracic and lumbar and two had both lumbar and sacral vertebral involvement. We detected posterior longitudinal ligament elevation in 11 patients, epidural abscess formation in 11 and paravertebral abscess formation in nine. Ten patients had cord compression and eight had root compression. Three patients had facet-joint involvement, and one had erector spinae muscle involvement. Eight patients (32%) were in the acute stage, six (24%) in the subacute stage and 11 (44%) in the chronic stage. Vertebral bodies, vertebral end plates and intervertebral disc spaces were hypointense and hyperintense in the acute stage, whereas they were hypointense and heterogeneous in the subacute and chronic stages on T1- and T2-weighted images, respectively. In the acute stage on the DWI series, vertebral bodies, end plates and discs were all hyperintense but hypointense in the chronic stage.

CONCLUSIONS: Although conventional MRI has several advantages over other imaging modalities and is very useful in the differential diagnosis between brucellar spondylodiscitis and other spinal pathologies, it has some difficulties in discriminating acute and chronic forms of spondylodiscitis. DWI is a sensitive, fast sequence that has the potential for differentiating acute and chronic forms of spondylodiscitis, which makes it crucial in spinal imaging.