IMAGE OF THE WEEK
WEEK 32
CERVICAL SPONDYLODISCITIS
Figure 1a: Preop |
Figure 1b: Postop |
|
Assessment of the cervical spine radiograph includes 2 important aspects:
1. Bony alignment – there are a series of lines to assess
2. The anterior pre-vertebral soft tissues
BONY ALIGNMENT
Bony alignment consists of 3 key ‘lines’ which need to be reviewed. These are the:
a. Anterior vertebral line
b. Posterior vertebral line
c. Spinolaminar line
Figure 2a: C-spine illustration showing lines to assess on cervical radiograph |
Figure 2b: C-spine x-ray |
A very important aspect of assessment
of the cervical spine radiograph is the pre-vertebral soft tissues. Although
uncommonly abnormal, when abnormality arises it is often of great clinical
significance spinal.
The pre-vertebral soft tissues can provide signs of disease of the cervical
spine.
The anterior spinal soft tissues should have the dimensions as shown below if normal.
Figure 3: Soft tissue dimensions of C-spine |
The pre-vertebral soft tissues at C2 should measure less than 7mm or less
than 50% of the width of the adjacent vertebral body
The pre-vertebral soft tissue at C6 should measure less than 22mm. An
alternative assessment is to compare the width of the adjacent cervical
vertebral body. The pre-vertebral measurement should not be greater than the
width of the vertebral body.
In this case there is a significant widening of the pre-vertebral soft tissues anterior to C4 and C5 with displacement of the tracheal air column anteriorly. The C4-C5 disc space is obliterated and there is bony destruction of the adjacent end plates of C4 and C5, implying this is a pathology centred on the disc.
The appearances are consistent with a discitis with extension into the vertebral bodies and para-vertebral soft tissues, termed a spondylodiscitis.
Pyogenic infection, due to organisms such as Staphylococcus aureus, is the most common cause, although it is important to consider non-pyogenic causes, in particular tuberculosis.
MRI is the most sensitive form of imaging with a suspicion of spondylodiscitis, providing the most detail, both in terms of soft tissue characterisation, the status of the spinal canal. It also aids identification of an epidural abscess (see below in a different patient).
Figure 4: MRI Spine Post Contrast: Epidural Abscess |
Images contributed by Dr Ian Bickle, Department of Radiology, RIPAS Hospital, Brunei Darussalam.
All images are copyrighted and property of RIPAS Hospital.