Conventional bone scintigraphy has low to moderate sensitivity and variable specificity for the diagnosis of axSpA [41,42,50]. If bone scintigraphy is used, SPECT should be performed during the examination because of the complexity of the sacroiliac joint anatomy [51]. Although bone scintigraphy is not typically performed during the evaluation of suspected axSpA because of its limited diagnostic utility, there is recent data that hybrid SPECT/CT has higher sensitivity than conventional bone scintigraphy in the detection of sacroiliitis [52,53]. However, there is not enough evidence currently to support its routine use for evaluation of the sacroiliac joints and spine. Bone Scan with SPECT or SPECT/CT Sacroiliac Joints and Spine Area of Interest Bone scintigraphy is not routinely suggested in the evaluation of patients with suspected axSpA [22]. Conventional bone scintigraphy has low to moderate sensitivity and variable specificity for the diagnosis of axSpA [41,42,50]. If bone scintigraphy is used, because of the complexity of the sacroiliac joint anatomy, the use of SPECT should be performed during the examination [51]. Although bone scintigraphy is not typically performed during the evaluation of suspected axSpA because of its limited diagnostic utility, there is recent data that hybrid SPECT/CT has higher sensitivity than conventional bone scintigraphy in the detection of sacroiliitis [52,53]. However, there is not enough evidence currently to support its routine use for evaluation of the sacroiliac joints and spine. CT Sacroiliac Joints CT demonstrates the structural changes of sacroiliitis in patients with axSpA that may not be apparent on radiographs [22]. These structural changes, including erosions, sclerosis, bone formation, and ankylosis, are best demonstrated on sacroiliac protocol examinations that include obliquely oriented reformatted images prescribed parallel and perpendicular to the long axis of the sacrum [54].
Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. Conventional bone scintigraphy has low to moderate sensitivity and variable specificity for the diagnosis of axSpA [41,42,50]. If bone scintigraphy is used, SPECT should be performed during the examination because of the complexity of the sacroiliac joint anatomy [51]. Although bone scintigraphy is not typically performed during the evaluation of suspected axSpA because of its limited diagnostic utility, there is recent data that hybrid SPECT/CT has higher sensitivity than conventional bone scintigraphy in the detection of sacroiliitis [52,53]. However, there is not enough evidence currently to support its routine use for evaluation of the sacroiliac joints and spine. Bone Scan with SPECT or SPECT/CT Sacroiliac Joints and Spine Area of Interest Bone scintigraphy is not routinely suggested in the evaluation of patients with suspected axSpA [22]. Conventional bone scintigraphy has low to moderate sensitivity and variable specificity for the diagnosis of axSpA [41,42,50]. If bone scintigraphy is used, because of the complexity of the sacroiliac joint anatomy, the use of SPECT should be performed during the examination [51]. Although bone scintigraphy is not typically performed during the evaluation of suspected axSpA because of its limited diagnostic utility, there is recent data that hybrid SPECT/CT has higher sensitivity than conventional bone scintigraphy in the detection of sacroiliitis [52,53]. However, there is not enough evidence currently to support its routine use for evaluation of the sacroiliac joints and spine. CT Sacroiliac Joints CT demonstrates the structural changes of sacroiliitis in patients with axSpA that may not be apparent on radiographs [22]. These structural changes, including erosions, sclerosis, bone formation, and ankylosis, are best demonstrated on sacroiliac protocol examinations that include obliquely oriented reformatted images prescribed parallel and perpendicular to the long axis of the sacrum [54].