Flashcards in Clinical Assessment of the Spine Deck (67):
How are patients presenting with spinal problems assessed?
Consultation and physical exam
Histo-pathological and medical diagnostic tests
What is the most common manifestation of abnormal pathology?
What will the physician ask the patient?
To localize and describe the pain.
What factors are important to assess?
Its onset, duration and nature of the pain and the factors which exacerbate or alleviate it.
What are some neurological symptoms that will also be assessed?
Paraesthesia (pins and needles), numbness, weakness or incontinence.
What does the clinician do during the physical examination?
Note any deformity or asymmetry and any changes in normal movement or function of the spine and relevant associated structures.
What are the most commonly used imaging tools in diagnostics?
In an x-ray, what does the visibility of a structure depend upon?
Its radio-opacity which is a function of its atomic weight. The greater its atomic weight the more clearly it will show on x-ray.
What are the atomic weights of different parts of the body?
Calcium - 40
Iron in haemoglobin - 56
Sulpher in the collagen molecules of fascia - 32
Fat, water and carbohydrate are hardly visible.
How can one visualize structures of a low atomic weight?
Inject a contrast medium such as Barium 137 or Iodine 127 with heavier weights. These are either absorbed or surround structures providing greater visibility.
What is the main limitation of x-ray?
Its inability to demonstrate intra or extra spinal soft tissue injury or pathology.
Why are early stages of pathologic bone destruction difficult to see in an x-ray?
30% - 40% of the bone must be destroyed before it will clearly register on x-ray.
What is tomography?
A radiograph that permits more accurate visualization of lesions, or demonstrates anatomic detail obscured by overlying structures.
What planes can tomography scans be taken in?
Coronal, transverse or oblique planes.
When is plain tomography used?
To assess vertebral abnormalities such as hemi vertebrae. It can also be used to assess bone density in a spinal fusion.
Has been primarily replaced by CT and MRI.
Iodine solution is injected into the spinal theca where it mixes with the CSF to outline the spinal canal and nerve roots.
What is the theca?
The thecal sac is a membrane of dura mater that surrounds the spinal cord and the cauda equina.
What is discography?
Under local anesthetic a radio-opaque contrast medium is injected into the disc.
What are the two applications of a discography?
Firstly, it will enable the clinician to visualize any defect within the disc, and secondly, the increase in pressure as the contrast medium is injected may cause the patient to experience their usual pain symptoms.
Remains a controversial diagnostic tool.
Be careful to use in elderly patients in the cervical region because the relative weakness of the annulus can result in false positives.
What are the most common complications following a discography as it is an invasive procedure.
Headaches, infection, radicular pain and needle breakage.
What is computerized tomography CT used for?
Primarily used to image bones and joints.
How is a CT image created?
By rotating an x-ray beam through 360° around the patient. The resultant images are processed by a computer to create an image that grades tissue through a scale from black to white dependent upon density.
When is CT usually used?
To provide further information about a suspected pathology, and to define soft tissue pathology which is not clearly seen on x-ray.
Does a CT enable the clinician to take multiple cross-sectional images of the spine at various levels?
What is the width of a CT slice?
1mm enabling a clear three dimensional image of the spine to be built.
What does CT show in addition to bone?
Soft tissue is seen in varying degrees of shading. Ligaments, fat, nerve roots and disc protrusions can be seen in relation to the bone.
What is CT good at diagnosing?
Distinguish between hard (osteophytes) and soft (herniated nucleus pulposus) discs
Also excellent in diagnosing neoplastic lesions and infections.
How can CT be used in surgery?
As a guidance tool during surgery to allow the positioning of instruments.
What is a limitation of CT?
Distortion of images if metal is present in the area being scanned.
Not good for postoperative imaging of instrumented an area.
Not good for intrathecal pathology without contrast material.
What is CT commonly used in conjunction with when diagnosing intrathecal pathology?
What does an MRI provide?
Multi-planar images and avoids the possible complications associated with contrast mediums.
What is an MRI's strengths?
It can clearly define soft tissue and characterize the pathologies.
How does an MRI use to create its images?
An MRI is basically a big magnet. Huge. Giant.
You are a bag of fluid filled with hydrogen atoms.
When the magnet spins around you while you're in the tube, it makes some of the the hydrogen atoms ~1/100,000 orient in a direction and wobble within that orientation.
A "ping sound" at a frequency matched to the frequency of the wobble of these oriented, wobbling, hydrogen atoms is played and it causes them to flip to their opposite orientation.
These flipped hydrogen atoms return to their original orientation over time (the time depends on the tissue you are focusing on) and as they do they release energy that is picked up by the machine.
This energy is read and standardized and based on the speed of orientation recovery we can create an image.
An fMRI (functional magnetic resonance image) does basically the same thing, but in your brain with oxygen atoms.
What does a bright white area in the MRI scan signify?
High signal intensity.
What does a dark black area in the MRI scan signify?
Low signal intensity.
What are the longitudinal and transverse relaxation time of the protons called?
T1 and T2 - nothing to do with thoracic
What does the T1 (longitudinal relaxation time) measure?
The return of the equilibrium following the application and removal of the radio frequency pulse.
What dose the T1 demonstrate?
The normal anatomy because the short relaxation and acquisition time.
Describe radioisotope scanning (Scintigraphy)
A radioactive compound is injected intravenously into the target tissue. Indicated in diagnosis of persistent pain when no clinical or radiological cause is found. Useful in confirming tumors, infection and abnormal osteoblastic activity. Not common because of issues associated with radioactive material.
What is the most frequently used diagnostic tool?
What can x-rays detect?
Deformity, tumors, infection, inflammatory diseases and trauma.
What are the different view options of a cervical spine x-ray?
What will a clinician assess when observing a cervical spine x-ray?
The number of vertebrae and their alignment.
The alignment of the bodies should be checked anteriorly and posteriorly.
The normal cervical spine has a lordotic curve and up to 3mm of physiological subluxation between adjacent vertebral bodies.
a slight misalignment of the vertebrae, regarded in chiropractic theory as the cause of many health problems.
What areas of the cervical spine are examined for evidence of pathology?
Vertebral body morphology, disc space, facet joints, and soft tissue shadows.
What does one check for when examining the odontoid process?
That it is intact and aligned correctly to the anterior arch of the atlas. There is usually 3mm between the two structures.
Do PA and lateral views offer adequate views of C1 and C2?
When is a trans-oral image used?
To assess the C1 C2 level. In this view the odontoid process, atlas and atlanto-axial joints are clearly seen.
What does one look for when assessing the C1 and C2?
The lateral masses of the atlas should be perfectly aligned with the body of C2 and the distance from either lateral mass to the odontoid should be equal.
What are uncovertebral joints?
are formed between uncinate processes below, and the uncus above. They are located in the cervical region of the vertebral column between C3 and C7. Two lips project upward from the superior surface of the vertebral body below, and one projects downward from the inferior surface of vertebral body above. They allow for flexion and extension and limit lateral flexion in the cervical spine.
What is the uncinate process?
An uncinate process of a vertebra is a hook-shaped process on the lateral borders (side edges) of the superior (top) surface of the vertebral bodies of the third to the seventh cervical vertebrae and first thoracic vertebra. This bony part prevents a vertebra from sliding backwards off the vertebra below it (i.e. it prevents posterior linear translation movements of the vertebral bodies) and limits lateral flexion (side-bending). Luschka's joints involve the vertebral uncinate processes.
What appears white in a T2 MRI image?
The cervical spine, CSF and the nucleus of the intervertebral disc. The spinal cord will appear grey. This is because of the high water content in the CSF giving a high intensity signal.
What are T1 MRI images used to demonstrate?
What are T2 MRI images used to demonstrate?
In a thoracic spine x-ray, where does bony examination start?
With the alignment of the spinous processes.
What should be seen in the disc space throughout the thoracic spine?
The space should be even and the intervertebral foramina should be the appropriate size and shape at each level
What should one look for with regards to the inter-pedicular distance?
They should be equal at each level.
What is a CT used for when imaging the thoracic spine?
CT is used to image the intervertebral disc space or the vertebral bodies. Can get a clear view when the x-ray was obstructed by overlying ribs and soft tissue.
What will a CT scan show at the vertebral body level?
The pedicles and the transverse processes with their rib articulations at the costal facets.
What will a CT scan show at the intervertebral level?
The spinal canal, spinal cord and the facet joints.
What color will the CSF be in a T1 weighted MRI?
What are the typical views taken in the lumbar spine?
PA and lateral.
What does one look for when assessing the lumbar spine?
The correct lumbar lordosis
Spinous processes should be properly aligned
Vertebral bodies should be the correct shape and align with the adjacent vertebral bodies.
2 pedicles should be visible at each level and in their correct positions.
Discs should be at their correct height and shape.
Facet joints should be clearly visible and of similar shape and size.
What is occasionally used for diagnosis of fractures of the pars interarticularis and conditions of the facet joints?
A 45° oblique x-ray
What is a CT of the thoraco-lumbar used to image?
The vertebral bodies, the facet joints, pedicles, transverse processes and the boundaries of the spinal canal. At the sacrum the promontory, ala and sacroiliac joints can be seen.
What does a CT provide with regards to muscles in the lumbar region of the spine?
The deep musculature and allows clear visualization of the psoas muscle and the paravertebral musculature of the lumbar spine.