Ground Floor
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.
Figure 1 & 2. MRI assessment of child with right sided sciatica demonstrates loss of the normal bright signal as well as the height of the L5/S1 disc. The other discs may be used as reference for the expected signal and height of the disc. The lower signal of the L5 disc is accounted for by the decrease amount of fluid within the disc, known as desiccation. Thus the discs above this level which have preserved their water content, will be brighter relative to the L5/S1 disc as water provides the disc with its high signal (as well as ability to withstand forces). When the disc material herniates beyond its margin, displacement of the nerves can occur, as in this case the right S1 nerve on the axial image provided, which is the cause of the child’s pain. Note the higher discs demonstrate irregularity of the endplate (vertebral bone margin adjacent to the disc, labelled S). These are small focal areas of developmental herniation of the disc into the endplate known as Schmorl’s nodes and are an extremely common finding.
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).
Figure 3 & 4. MRI assessment of the spine to assess for the presence ofspondylolysis, 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
MRI scans of the spine (cervical, thoracic, lumbar and sacral spine) in children under 16 that are eligible for the Medicare rebate referred by GPs are bulk billed* at Melbourne Radiology Clinic.
Referral by a medical practitioner (excluding a specialist or consultant physician) for a scan of spine for a patient under 16 years where:
BULK-BILLED*
a previous radiographic examination must have been performed
