Abstract
This article reviews the utility of imaging in the diagnostic work-up of suspected
and undifferentiated axial and peripheral inflammatory arthritis. Radiographic findings,
that is, late damage but not early inflammation, are part of the classification criteria
for rheumatoid arthritis (RA), ankylosing spondylitis, spondyloarthritis (SpA), and
psoriatic arthritis (PsA), and they are generally part of the early examination program
in arthritis.
Computed tomography visualizes calcified tissue with high resolution but is rarely
used unless radiography is unclear and MRI unavailable.
MRI and ultrasonography (US) allow sensitive visualization and assessment of peripheral
inflammatory and destructive joint and soft tissue involvement, and MRI is by far
the best available method for detecting inflammation in the spine and sacroiliac joints
in early SpA. Thus MRI/US can contribute to an earlier diagnosis of RA, PsA, and SpA.
MRI and US are part of the recent American College of Rheumatology/European League
against Rheumatism 2010 classification criteria for RA (can be used to count involved
joints), and MRI is part of the SpondyloArthritis International Society criteria for
axial and peripheral SpA.
Thus radiography, MRI, and/or US should be used in clinical practice to contribute
to the diagnostic work-up in suspected, but not definite, inflammatory joint disease
and early unclassified inflammatory joint disease, and they are also useful in establishing
a specific diagnosis of RA. Radiography and particularly MRI are essential in establishing
an early diagnosis of axial SpA.
Keywords
undifferentiated arthritis - rheumatoid arthritis - spondyloarthritis - radiography
- magnetic resonance imaging - ultrasonography
