Frederiek Laloo1, Nele Herregods2, Jacob L Jaremko3, Philippe Carron4, Dirk Elewaut5, Filip Van den Bosch6, Koenraad Verstraete7, Lennart Jans8. 1. Department of Radiology and Medical Imaging, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium. Electronic address: frederiek.laloo@gmail.com. 2. Department of Radiology and Medical Imaging, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium. Electronic address: nele.herregods@uzgent.be. 3. Department of Radiology & Diagnostic Imaging, University of Alberta Hospital, 8440-112 Street, Edmonton T6G 2B7, Alberta, Canada. Electronic address: jjaremko@ualberta.ca. 4. Department of Rheumatology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium; VIB Inflammation Research Center, Unit for Molecular Immunology and Inflammation, Ghent University, Technologiepark 927, B-9052 Gent, Belgium. Electronic address: philippe.carron@ugent.be. 5. Department of Rheumatology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium; VIB Inflammation Research Center, Unit for Molecular Immunology and Inflammation, Ghent University, Technologiepark 927, B-9052 Gent, Belgium. Electronic address: dirk.elewaut@ugent.be. 6. Department of Rheumatology, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium; VIB Inflammation Research Center, Unit for Molecular Immunology and Inflammation, Ghent University, Technologiepark 927, B-9052 Gent, Belgium. Electronic address: filip.vandenbosch@ugent.be. 7. Department of Radiology and Medical Imaging, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium. Electronic address: koenraad.verstraete@ugent.be. 8. Department of Radiology and Medical Imaging, Ghent University Hospital, Corneel Heymanslaan 10, B-9000 Gent, Belgium. Electronic address: lennart.jans@ugent.be.
Abstract
OBJECTIVES: To study the presence of high signal intensity of the intervertebral disc, syndesmophytes, vertebral corner bridging and transdiscal ankylosis on spinal T1-weighted MR images in spondyloarthritis (SpA). METHODS: A retrospective case-control study of whole spine MRI examinations, obtained in 100 patients with axial SpA and in 100 control patients, was performed. All disco-vertebral units (DVUs) were analyzed on T1-weighted MR images for normal or high signal intensity of the intervertebral disc, presence of syndesmophytes, vertebral corner bridging or transdiscal ankylosis and correlated with final diagnosis. Sensitivity, specificity, and positive and negative likelihood ratios were calculated. RESULTS: In this study group, intradiscal high signal intensity, vertebral corner bridging and transdiscal ankylosis on T1-weighted MR images of the spine were all highly specific (specificity: 100%) for diagnosis of axial SpA. However, these signs all had low sensitivity (vertebral corner bridging: 15.0%; intradiscal high signal intensity on T1-weighted MR images: 12.0%; transdiscal ankylosis: 8.0%). Syndesmophytes on spinal MRI were observed in 25 patients but had a more limited diagnostic value (sensitivity: 16.0%, specificity: 91.0%). CONCLUSIONS: When present in a patient with inflammatory back pain, intradiscal high signal intensity on T1-weighted MR images could be a specific and reliable sign of the presence of axial SpA. Vertebral corner bridging and transdiscal ankylosis also show potential as specific and reliable signs of axial SpA. In contrast, syndesmophytes on MRI do not show potential as a specific or reliable sign of axial SpA.
OBJECTIVES: To study the presence of high signal intensity of the intervertebral disc, syndesmophytes, vertebral corner bridging and transdiscal ankylosis on spinal T1-weighted MR images in spondyloarthritis (SpA). METHODS: A retrospective case-control study of whole spine MRI examinations, obtained in 100 patients with axial SpA and in 100 control patients, was performed. All disco-vertebral units (DVUs) were analyzed on T1-weighted MR images for normal or high signal intensity of the intervertebral disc, presence of syndesmophytes, vertebral corner bridging or transdiscal ankylosis and correlated with final diagnosis. Sensitivity, specificity, and positive and negative likelihood ratios were calculated. RESULTS: In this study group, intradiscal high signal intensity, vertebral corner bridging and transdiscal ankylosis on T1-weighted MR images of the spine were all highly specific (specificity: 100%) for diagnosis of axial SpA. However, these signs all had low sensitivity (vertebral corner bridging: 15.0%; intradiscal high signal intensity on T1-weighted MR images: 12.0%; transdiscal ankylosis: 8.0%). Syndesmophytes on spinal MRI were observed in 25 patients but had a more limited diagnostic value (sensitivity: 16.0%, specificity: 91.0%). CONCLUSIONS: When present in a patient with inflammatory back pain, intradiscal high signal intensity on T1-weighted MR images could be a specific and reliable sign of the presence of axial SpA. Vertebral corner bridging and transdiscal ankylosis also show potential as specific and reliable signs of axial SpA. In contrast, syndesmophytes on MRI do not show potential as a specific or reliable sign of axial SpA.