From the Research
For an upright MRI to assess craniocervical instability, I recommend requesting: "Upright MRI of the cervical spine and craniocervical junction with flexion and extension views to evaluate for craniocervical instability, including measurements of the basion-axial interval, basion-axial angle, basion-dens interval, and the Grabb-Oakes line, as established by recent studies 1." This wording specifies the need for positional imaging (flexion and extension) which is crucial for detecting dynamic instability that may not be apparent in standard supine imaging. The upright position allows gravity to influence the structures, potentially revealing instability that would be missed in a recumbent position. Be sure to include any relevant clinical history such as connective tissue disorders, trauma, or specific symptoms like positional headaches, dizziness, or neurological symptoms that worsen with certain head positions. This information helps the radiologist focus their assessment on clinically relevant findings and provides context for interpreting subtle abnormalities that might indicate instability at the craniocervical junction.
Some key points to consider when assessing craniocervical instability include:
- The importance of evaluating the relationship between the skull base and upper cervical vertebrae, as described in studies such as 1 and 2
- The need to assess for abnormal movement between these structures, which can be achieved through positional imaging 1
- The measurement of specific parameters, such as the basion-axial interval, basion-axial angle, basion-dens interval, and the Grabb-Oakes line, to evaluate for craniocervical instability 1
- The potential for craniocervical dissociation spectrum injuries and atlantoaxial instability to guide neurosurgical management, as discussed in 2
By prioritizing the most recent and highest quality study 1, we can ensure that our assessment of craniocervical instability is based on the most up-to-date and reliable evidence.