Type:
Educational Exhibit
Keywords:
Musculoskeletal system, Conventional radiography, MR, CT, Diagnostic procedure, Arthritides
Authors:
F. Paparo1, E. Aleo2, M. Revelli1, L.-P. Rollandi2, L. Cevasco2, A. Garlaschi2, C. Puppo2, M. A. Cimmino1, A. Leone3; 1Genova/IT, 2Genoa/IT, 3Rome/IT
DOI:
10.1594/ecr2013/C-0478
Background
The inflammatory involvement of the spine and sacroiliac joints is the most peculiar feature of seronegative spondyloarthropathies (SpA),
which include ankylosing spondylitis,
psoriatic spondyloarthritis,
reactive spondyloarthritis (Reiter's syndrome),
enteropathic spondyloarthritis (related to inflammatory bowel diseases such as Crohn's disease and ulcerative colitis),
undifferentiated spondyloarthropathies and SAPHO syndrome.
The main clinical manifestations of SpA include inflammatory back pain caused by sacroiliitis or inflammatory involvement of the lumbar and/or distal thoracic spine; peripheral arthritis (often oligoarticular and asymmetric); enthesitis and extraskeletal manifestations,
such as uveitis.
In SpA,
the most characteristic targets of the autoimmune process are entheses,
anatomical structures made of fibrous or fibro-cartilaginous tissue,
which provide anchorage of tendons and ligaments to the bone surface.
Enthesitis is accompanied by the appearance of small erosions in the cortical bone,
typically surrounded by subcortical reactive osteosclerosis (osteitis),
which can often prevail over bone reabsorption; in the later stages osteoproliferation leads to the ossification of ligaments,
tendons and joint capsules,
and,
eventually,
to ankylosis.
Imaging,
along with clinical and laboratoristic evaluation,
is an important tool to reach a correct diagnosis and to provide a precise grading of disease progression,
influencing both clinical management and therapy.
Conventional radiography,
which is often the first-step imaging modality in SpA,
does not allow an early diagnosis.
Computed Tomography (CT) demonstrates with a very high spatial resolution the tiny structural alterations of cortical and spongy bone before they become evident on plain film radiographs.
Magnetic Resonance Imaging (MRI) is the only modality that provides demonstration of bone marrow oedema,
which reflects vasodilatation and inflammatory hyperemia.