Background Several sets of criteria exist for the diagnosis of spondyarthropathies (SpA), a group of related rheumatological disorders involving the axial spine. Despite the many modifications to the diagnostic criteria by incorporating clinical signs, imaging and biochemical studies, there continues to be a significant lag between disease onset and diagnosis. The new ASAS criteria may allow shorter diagnostic delay by incorporating MRI1.
Objectives A reaudit of all MRI spine scans performed to a locally developed Ankylosing Spondylitis protocols for radiological evidence of SpAs, to assess the positive ‘hit rate’ over one year. The initial audit was from 2009-10 and the current period is 2010-11.
Methods A total of 145 patients were obtained over the complete audit period. Details of patients MRI scans were obtained using the CRIS software search function to find data on patient demographics, referring physicians and respective departments, time to scan, time to report, the reporting radiologists’ specialty, and the positive diagnostic rates of all MRIs performed. Local and national standards were used for the audit. These were; A positive of ‘hit rate’ 90% for MRIs. SpA’ hit – rate’ of 60%. Consultants referrers 100%. AS Standard protocol- 100%. Time to report - not more than 2 weeks. Time to scan- not more than 18 weeks
Results 90% of scans were requested by rheumatology department throughout entire audit cycle. AS protocol MRI scans increased to 91% from 74%. Referrer grade improved upon reaudit from an intial 72% to 100% consultant only referrals. As illustrated in figure 1 in terms of hit rate; 8% of MRI scans normal compared to initial 14%. There was an increase in the detection of SpAs from 1% to 13% upon reaudit
Conclusions: Discussion Studies show standard clinical protocols may omit inflammatory lesions in thoracic region, which highlights the need for following spinal AS protocols2. The numbers of patients scanned to a standard ‘Neuroradiology’ spine protocol have significantly decreased due to radiographer education across the Trust. During the reaudit period, requests for MRI spine via AS protocol increased as well as consultant only referrals. The majority of referrals for MRI spine were from rheumatology and remained within the main specialist centre. The emphasis on experienced specialist input as well as the increase in the appropriate protocol for MRI spine, AS protocol, may contribute to the subsequent increase in diagnostic hit rate for inflammatory spine disease and SpAs shown in this audit.
Sieper J et al. The Assessment of SpondyloArthritis international Society (ASAS) handbook:a guide to assess spondyloarthritis. Ann Rheum Dis 2009;68;ii1-ii44 doi:10.1136/ard.2008.104018
Rennie WJ. Magnetic resonance imaging assessment of spinal inflammation in ankylosing spondylitis: standard clinical protocols may omit inflammatory lesions in thoracic vertebrae. Arthritis Rheum. 2009 Sep 15;61(9):1187-93
Disclosure of Interest None Declared