Imaging the Spine Flashcards
What do x-rays show?
Bone outlines
What do CT scans show?
Bone outlines in more detail and some soft tissue structures
What do MRI scans show?
Bone outlines in less details but show bone marrow, discs, ligaments, the spinal cord and nerves (e.g all soft tissue structures)
What can be used to image bones?
X-ray, CT and MRI
What can be used to image soft tissues?
CT and especially MRI
What helps to form the natural smooth curve of the spine?
Cervical lordosis, thoracic kyphosis and lumbar lordosis
What can be used to show the normal curvature of the spine?
CT and MRI
What are the common features of the 3rd to 7th C vertebrae, 12 T vertebrae and 5 L vertebrae?
Vertebral body
Posterior arch = 2 pedicles, 2 laminae, 1 spinous process, 2 transverse processes
Where is the neural foramen located?
Inferior to the pedicle
What forms facet joints?
The anterior and posterior projections of the articular processes between the pedicles and laminae
What view can be used to identify normal anatomical features?
AP view
What is unusual about C1?
Has no vertebral body = comprises anterior and posterior arches, united by two large vertebral masses, articulates with occipital bone and C2
What is unusual about C2?
Has odontoid process = projects superiorly into C1, anterior to the spinal canal, where it forms a joint with C! anterior arch
When are CT scans used to image spinal trauma?
When x-ray shows feature but more detail is needed and to check if any more injuries are present
When is x-ray is normal but there is high clinical suspicion
What are the functions of the intervertebral ligaments?
Tether vertebrae together and are responsible for spinal stability
How can x-rays and CT scans be used to image the intervertebral ligaments?
Not visible on these imaging modalities = seeing normal vertebral alignment on these tests implies intact ligaments and a stable spine
What is the only imaging test that shows ligaments?
MRI = normal ligaments appear black, damaged ligaments are light
When are MRI scans used to image spinal trauma?
Occasionally to provide detail of spinal ligaments
In patients with neurological deficit which isn’t explained by CT or x-ray
Show soft tissue abnormalities = acute prolapsed disc, epidural haematoma, spinal cord damage
What are x-ray and CT features of vertebral tumours?
Bone sclerosis = increased bone density
Bone destruction = reduced bone density
Vertebral collapse
What are features of vertebral tumours unique to MRIs?
Early = bone marrow infiltration Late = extradural mass and spinal cord compression
What is the function of intervertebral discs?
Cushion vertebrae from stress
What may happen to intervertebral discs as a prelude to disease?
May dehydrate
What may happen to a dehydrated intervertebral disc?
Disc material may herniate through disc lining into spinal canal and may press on spinal nerve, causing sciatica
How do prolapsed intervertebral discs present on x-rays?
May show narrowing of disc space
What kind of prolapsed disc is visible on CT scans?
Lower lumbar scans
What is the best modality for imaging the intervertebral discs?
MRI = shows all disc prolapses and preceding disc dehydration
How effective are the imaging techniques for capturing the spinal cord?
Invisible on x-rays
Poorly shown on CT
Only adequately shown on MRI
What are some causes of spinal cord disease?
Trauma, tumour, demyelination, ischaemia
