Imaging modalities for cervical spondylosis aim to assist the clinician in differentiating discogenic neck pain, radiculopathy, and myelopathy. Radiological assessment helps to localise the site and level of the disease for preoperative planning when surgical intervention is required. The current modalities in common use are pain film roentgenology, magnetic resonance imaging, and computed tomography.
Despite advances in diagnostic imaging plain film remains an inexpensive initial radiological evaluation of the spine in cervical spondylosis. Anteroposterior, lateral, and oblique radiographs can be acquired easily at the time of consultation. These images can show changes in the facet and uncovertebral, osteophytes, and disc space [1
]. This is an indication of the underlying pathology but not diagnostic as these findings are common in the adult population [1
]. Weight-bearing plain films can also assess alignment and sagittal canal diameter. Measurement of the anteroposterior diameter is typically determined on a lateral plain film as the distance from the posterior surface of the vertebral body to the closest point on the spinolaminar line at the pedicle level. However, this is a two-dimensional assessment of a three-dimensional structure and such measurements have shown to be inaccurate. Three-dimensional imaging modalities are now used for more accurate assessment. Lateral flexion-extention views are also useful initial investigations [2
]. These will help to assess cervical range of motion and identify fused segments and instability. Instability is suggested where translation of >3.5
mm and sagittal plane angulation of >11
degrees are present [3
Compared with other radiological studies available to evaluate the spine magnetic resonance imaging (MRI) provides the greatest range of information [4
]. It provides an accurate morphological assessment of both osseous and soft tissue structures including intervertebral discs, spinal ligaments, and the neural elements. Dynamic weight bearing MRI has recently been championed as the preferred technique for pathology-specific diagnosis [5
]. Computed tomography in isolation lacks the soft tissue detail achieved with MRI scanning. However, CT is still a useful modality when there is a contraindication to MRI and where metal artefact is obstructing the anatomy. CT myelography is an invasive procedure and is associated with a number of risks. It is only used for patients who have contraindications, equivocal findings, or failed MR imaging because of metal artefact.
Imaging for spinal stenosis should aim to determine the site of compression. Spinal stenosis can be divided into central, subarticular recess (lateral recess), and lateral [7
]. Central stenosis results in concentric narrowing of the spinal canal and can result in cervical myelopathy. Radicular symptoms can be attributed to either subarticular recess stenosis in lateral aspect of the central spinal canal or lateral stenosis at the foramina. Radiological evaluation of the spinal cervical spine can as such be broadly slit into central and lateral.