MRI of the spine is indicated for the assessment of neurological disorders of the limbs, as well as pain (commonly referred to as sciatica in the leg and brachalgia in the arm). Causes include disc lesions, tumours, trauma as well as developmental abnormalities of the spinal cord and surrounding structures.
Another common indication for MRI assessment of the spine is to assess for the presence of spondylolysis, also known as a pars interarticularis fracture/defect (or more simply, a “pars” fracture/defect) (arrows).
This solid block of bone forms during early childhood. Thus, in patients with a weakness in this region and/or those who undertake excessive activities, the bone may either fail to develop adequately and thus result in a defect. Alternatively, due to overuse, abnormal biomechanics and/or a predisposition to this condition, the pars may fracture as it is starting to form or early thereafter. This may then result in forward slipping of the vertebral body on top relative to that one situated below, as there is now disconnect between the anterior (front) and posterior (back) elements, a finding known as anterolisthesis (one of the subtypes of spondylolisthesis). The condition typically causes lower back pain and is treated with rest and strengthening of core muscles. If the degree of anterolisthesis is severe and/or the pain continues despite maximal conservative therapy, then surgical fixation may eventually be required.
Figure 5. Axial images through the cervical spine in a paediatric patient demonstrates a tiny central hyperintense (bright) focus of the central spinal cord, known as a syrinx