Infectious spondylitis. A retrospective evaluation of the MRI signs

Aim and methods: The aim of the present study was to evaluate the MRI criteria of infectious spondyIitis (spondylodiscitis). The MR images of 23 patients suffering from spondylodiscitis (78% unspecific, 22% specific) were retrospectively analyzed. Results: The height of the intervertebral discs involved was normal in 40%, reduced in 43% and increased in 17% of the cases. The most common findings can be summarized in an MR triad: 1) The vertebral bodies involved are hypointense in T1-weighted images (100%) with a lack of delineation of the intervertebral discs (53%), 2) The injection of Gd-DTPA yields an enhancement of the vertebral bodies involved and intervertebral discs (95% and 74% respectively). 3) The vertebral bodies and intervertebral discs are hyperintense in T2-weighted sequences (76% and 90% respectively). When present, a paravertebral or intraspinal extension of the infection was isointense compared with the adjacent involved vertebral body in the majority of the patients. A differentiation between unspecific and specific etiology based on the MR images was not possible. Conclusions: The vertebral bodies affected were usually hypointense in T1-W with enhancement after the administration of G-DTPA and hyperintense in T2-W. The discs involved were usually hyperintense in T2-W and demonstrated an inhomogeneous enhancement.