The sensitivities of CT and MRI for fracture detection are similar in the available small case series, notably with some fractures better detected on CT and some better detected on MRI, suggesting these modalities have a degree of complementary diagnostic utility [34,160,161]. MRI, similar to CT, has higher sensitivity for detection of fracture in the setting of ankylosis than radiographs [32,34,161]. MRI can detect both osseous fractures as well as soft tissue injuries such as ligamentous disruption or spinal cord injury [31,34,160]. In the setting of neurologic deficit, MRI should be performed, either as the sole cross-sectional imaging modality or in addition to CT [22,162]. The cervical spine is most frequently involved by fracture [32,33,35]. The presence of two or more fractures is common [160], and therefore the entire spine should be imaged to both ensure detection of the potential fracture(s) and to detect multilevel involvement [32]. Radiography Spine Area of Interest Radiography of the spine can be considered as an initial imaging modality in patients with axSpA and suspected fracture [22], although fractures can be difficult to detect on radiographs in axSpA patients, especially in the setting of structural abnormalities and osteopenia, contributing further to an already inherent lower sensitivity of radiography for fracture detection compared with CT or MRI [31,32,34,160,161]. Negative radiographs in these patients should be followed by cross-sectional imaging. If obtained, radiographs should cover the entire spine in patients with ankylosis and suspected fracture because of the potential for multilevel fractures [32,160].
Inflammatory Back Pain Known or Suspected Axial Spondyloarthropathy PCAs. The sensitivities of CT and MRI for fracture detection are similar in the available small case series, notably with some fractures better detected on CT and some better detected on MRI, suggesting these modalities have a degree of complementary diagnostic utility [34,160,161]. MRI, similar to CT, has higher sensitivity for detection of fracture in the setting of ankylosis than radiographs [32,34,161]. MRI can detect both osseous fractures as well as soft tissue injuries such as ligamentous disruption or spinal cord injury [31,34,160]. In the setting of neurologic deficit, MRI should be performed, either as the sole cross-sectional imaging modality or in addition to CT [22,162]. The cervical spine is most frequently involved by fracture [32,33,35]. The presence of two or more fractures is common [160], and therefore the entire spine should be imaged to both ensure detection of the potential fracture(s) and to detect multilevel involvement [32]. Radiography Spine Area of Interest Radiography of the spine can be considered as an initial imaging modality in patients with axSpA and suspected fracture [22], although fractures can be difficult to detect on radiographs in axSpA patients, especially in the setting of structural abnormalities and osteopenia, contributing further to an already inherent lower sensitivity of radiography for fracture detection compared with CT or MRI [31,32,34,160,161]. Negative radiographs in these patients should be followed by cross-sectional imaging. If obtained, radiographs should cover the entire spine in patients with ankylosis and suspected fracture because of the potential for multilevel fractures [32,160].