Marginal erosive discovertebral "Romanus" lesions in ankylosing spondylitis demonstrated by contrast enhanced Gd-DTPA magnetic resonance imaging

Objective. To assess the value of Gd-DTPA magnetic resonance (MR) imaging i n the demonstration of marginal destructive discovertebral Romanus lesions in ankylosing spondylitis, Design ann patients. A prospective study of Gd-DTPA MR imaging was performe d in 39 patients with a clinical diagnosis of ankylosing spondylitis and ty pical Romanus lesions seen on radiographs of the thoracolumbar spine. MR mo rphological appearances and signal intensity changes at the discovertebral junctions were analysed and compared with the radiographic findings. Results. Ninety-nine discovertebral junctions with Romanus lesions showed l ow signal intensity on T1-weighted and high signal on T2-weighted and T1-we ighted postcontrast images at the vertebral corners consistent with oedemat ous hyperaemic inflammatory tissue, There were nine discovertebral junction s with similar MR findings but normal radiographs. Fifty-three discovertebr al junctions showed syndesmophyte formation with increased signal intensity on both T1- and T2-weighted images with no contrast enhancement. Sixty-fiv e discovertebral junctions showed a mixture of radiographic features and va ried high and low signal changes at the vertebral rim on MR imaging with ri ms of enhancement in the vertebral body following contrast administration. Conclusion, Gd-DTPA MR imaging demonstrates a variable signal pattern and d egree of contrast enhancement which may reflect the evolutionary stages of discovertebral enthesitis in ankylosing spondylitis, MR imaging may identif y early erosive changes in radiographically normal vertebra. The role of MR imaging needs further investigation.