Low-dose CT of the whole spine found more sensitive than conventional radiographs in monitoring AS
MADRID — In patients with ankylosing spondylitis, low-dose CT of the whole spine delivered greater sensitivity than imaging with conventional radiographs, according to a study presented at the EULAR Annual Congress.
“Most new and growth of syndesmophytes are observed in the thoracic spine on the [low-dose] LD-CT,” researcher Désirée van der Heijde, MD, told Healio.com/Rheumatology. “It is especially an option to view these syndesmophytes on the LD-CT, which makes a big difference in sensitivity compared to conventional radiographs, as the thoracic spine cannot be reliably assessed by radiographs.”
Van der Heijde and colleagues evaluated 50 patients (mean age, 48.6 years; 84% were male; 80% HLA-B27) recruited from the Sensitive Imaging of Axial Spondyloarthritis cohort from Leiden and Herne. Patients had at least one syndesmophyte on either the cervical and/or lumbar spine, based on modified NY criteria and viewed on conventional radiograph, or at least one inflammatory lesion seen on an MRI of the whole spine.
Patients underwent conventional radiography (CR) of the lateral cervical and lumbar spine and LD-CT (approximately 2mSV to 3 mSV) of the entire spine at baseline and at 2 years. Both the CR and CT scans were separately and independently evaluated by two readers. The images were paired per patient, and were blinded to time sequence, patient information and results attained with the other imaging approach. The researchers defined consensus about each of these outcomes as agreement of both readers on the same vertebral level. CR and CT data were compared per reader and for the consensus score.
The researchers found more patients with progression were detected on LD-CT. This was particularly evident in the monitoring of growth, as well as for cutoffs of a higher number of syndesmophytes per patient (newly formed or growth). In the strictest comparison of the consensus score for both CR and CT, CT captured bony proliferation (newly formed and growth) at a minimum of three sites in 30% of patients vs. 6% seen on CR. – by Jennifer Byrne
van der Heijde D, et al. Abstract #OP0114. Presented at: EULAR Annual Congress; June 14-17, 2017; Madrid.
Disclosure: The researchers report no relevant disclosures.