Do we need to perform MRI of the whole spine in addition to MRI of the sacroiliac joints in suspected spondyloarthropathy?

Abstract

To identify the incidence of spinal-only changes (including both acute inflammatory and chronic structural changes) in patients with suspected spondyloarthropathy (SpA) to determine whether MRI of the sacroiliac joints would be sufficient in the initial radiological work-up and whether the number of spinal magnetic resonance imaging (MRI) examinations performed could be reduced. This was a retrospective study of patients with suspected SpA referred from the rheumatology department of a university teaching hospital undergoing MRI both of the whole spine and of the sacroiliac joints over a 3-year period. Imaging was assessed for the presence of acute inflammatory and chronic structural changes. Three hundred and sixty-five patients with suspected SpA undergoing both whole spine and sacroiliac joint MRI were identified. The majority (79.2%) had no spinal or sacroiliac joint inflammation. Spinal-only changes (acute inflammatory and/or chronic structural) were detected in only 0.8% (3/365) of cases. The majority of positive spinal cases had inflammatory changes involving the thoracic spine (21/24). The majority of positive sacroiliac joint cases were bilateral (51/73). The extremely low incidence of spinal-only inflammatory or structural change indicates that sacroiliac joint MRI may be sufficient for initial radiological work-up of SpA with spinal MRI reserved for instances where there is spinal symptomatology and uncertainty in the clinical diagnosis following interdisciplinary discussion or where a baseline is required.