However, axSpA often involves the axial skeleton proximal to the sacroiliac joints and may exhibit findings isolated to the spine. For example, in a study of whole-body MRI in active axSpA, 99% of patients were found to have active inflammatory lesions in the axial skeleton, with inflammatory changes isolated to the sacroiliac joints in 52% of patients, inflammatory changes isolated to the spine in 5% of patients, and with inflammatory changes at both the sacroiliac joints and spine in 41% of patients [59]. Other studies have shown widely varying degrees of isolated spinal involvement on MRI ranging from 1% to 49% [19,60-63,114,115]. In early axSpA, it has been shown that inflammation involving both the sacroiliac joints and spine can be seen in 28.3% of patients [116]. Therefore, it can be useful in some cases to image both the sacroiliac joints and the spine to help ensure MRI yields the highest diagnostic utility and establishes the extent of disease burden. The decision on whether to image the spine as well as the sacroiliac joints could be based on the site of symptoms. Although there is some disagreement about the extent to which inflammatory changes in the axial skeleton correspond with symptoms, imaging the spine in the clinical region of interest is beneficial in the setting of referable symptoms [62,117-119]. Multiple authors utilize whole-spine or whole-body MRI to identify the burden of disease throughout the spine rather than imaging specific segments because findings may potentially be found in any portion of the spine [10,59,63,89,114,120-122]. The spine MRI findings of axSpA include the active inflammatory changes of spondylitis and spondylodiscitis, inflammatory changes of the costovertebral joints, costotransverse joints, and facet joints, and areas of enthesitis along other vertebral ligamentous attachments [123].
Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. However, axSpA often involves the axial skeleton proximal to the sacroiliac joints and may exhibit findings isolated to the spine. For example, in a study of whole-body MRI in active axSpA, 99% of patients were found to have active inflammatory lesions in the axial skeleton, with inflammatory changes isolated to the sacroiliac joints in 52% of patients, inflammatory changes isolated to the spine in 5% of patients, and with inflammatory changes at both the sacroiliac joints and spine in 41% of patients [59]. Other studies have shown widely varying degrees of isolated spinal involvement on MRI ranging from 1% to 49% [19,60-63,114,115]. In early axSpA, it has been shown that inflammation involving both the sacroiliac joints and spine can be seen in 28.3% of patients [116]. Therefore, it can be useful in some cases to image both the sacroiliac joints and the spine to help ensure MRI yields the highest diagnostic utility and establishes the extent of disease burden. The decision on whether to image the spine as well as the sacroiliac joints could be based on the site of symptoms. Although there is some disagreement about the extent to which inflammatory changes in the axial skeleton correspond with symptoms, imaging the spine in the clinical region of interest is beneficial in the setting of referable symptoms [62,117-119]. Multiple authors utilize whole-spine or whole-body MRI to identify the burden of disease throughout the spine rather than imaging specific segments because findings may potentially be found in any portion of the spine [10,59,63,89,114,120-122]. The spine MRI findings of axSpA include the active inflammatory changes of spondylitis and spondylodiscitis, inflammatory changes of the costovertebral joints, costotransverse joints, and facet joints, and areas of enthesitis along other vertebral ligamentous attachments [123].