X ray c-spine by Dr. Sulav Pradhan

1. Radiographic
Anatomy And
Positioning of
Cervical Spine
Dr Sulav Pradhan
Resident (first year)
Department of radiodiagnosis
NAMS, Bir Hospital

2. Topics to be discussed
• Anatomy
• Cervical spine systemic
approach
• Projection techniques
• Lines and angles of spine
• Common fractures

3. Anatomy of cervical spine

4. Cervical vertebrae
 2 TYPES
– Atypical
• Axis
• Atlas
• C 7
– Typical
• C 3-6

5. Typical Cervical Vertebrae
 has a vertebral body anteriorly and a
neural arch posteriorly
Neural arch – pedicles laterally and
laminae posteriorly
Foramen transversarium – distinct
feature , transmits vertebral artery(except
C7)
Transverse process- anterior and
posterior tubercles
Triangular vertebral canal
Spinous process- small and bifid

7. Atlas
• Doesn’t Have body &spinous
Process
• Its ring-like, has anterior and a
posterior arch and two lateral
masses
• Each lateral mass has superior
articular facet&inferior articular
facet
• Superior articular facet articulate
with occipital condyle- atlanto-
occipital joint (yes movement)
• Inferior articular facet articulate
with axis superior facet –atlanto-
axis joint(no movement)
• Transverse process project laterally
from lateral mass which is pierced
by foramen transversorium

8. AXI
S
• The most distinctive
characteristic
of this bone is the
strong odontoid
process ("dens") which
rises perpendicularly from
the upper surface of the
body
Axis

9. Cervical Vertebra (C7)
Long,easily felt with non bifid spine. So
the name vertebra prominens
 Foramen transversarium- small or
absent, usually transmits only vertebral
veins and not arteries
Anterior tubercle of transverse process
is smaller than the other cervical
vertebrae
Sometimes the anterior root of the
transverse process attains a large size and
exists as a separate bone, which is known
as a cervical rib

10. Ligamentous Anatomy
• Anterior longitudinal ligament
– Reinforces anterior discs, limits extension
• Posterior longitudinal ligament
– Reinforces posterior discs, limits flexion
• Ligamentum nuchae =
supraspinous ligament
– Thicker than in thoracic/lumbar regions
– Limits flexion
• Interspinous/intertransverse
ligament
– Limit flexion and rotation/limits lateral
flexion
• Ligamentum flavum
– Attach lamina of one vertebrae to
another, reinforces articular facets
– Limits flexion and rotation

12. Cervical Anatomy: Nutshell
Total 7 cervical vertebrae
Divided into typical(3,4,5 and 6)and
atypical(1,2 and 7)
All typical cervical vertebrae have foramen
transversarium and bifid spinous process
C1(atlas): has no body or spine,has short
anterior arch and long posterior arch
C2 (axis): has odontoid process
C7(Cervica prominens):has longest spinous
process which is non bifid and can be felt
subcutaneously

13. Cervical Spine Radiography
• Clinical considerations are particularly important
because
– normal C-spine X-rays cannot exclude significant injury
– a missed C-spine fracture can lead to death
– life long neurological deficit
• Imaging should not delay resuscitation.
• CT or MRI is often appropriate in the context of a
high risk injury, neurological deficit, limited clinical
examination, or where there are unclear X-ray findings

14. Cervical Spine Systemic Approach
ABCDE
• Adequate Coverage?
• Alignment
• Bodies- Vertebral body height/spinous
process
• Cortical Outlines
• Disc spacing
• Edges and Soft tissues

15. • Coverage - All vertebrae are visible from the skull base to
the top of T1 (T1 is considered adequate)
– If T1 is not visible 'swimmer's' view
• Alignment - Check the Anterior line (the line of the
anterior longitudinal ligament), the Posterior line (the
line of the posterior longitudinal ligament), and the
Spinolaminar line (the line formed by the anterior edge
of the spinous processes - extends from inner edge of
skull)
• Bone - Trace the cortical outline
• Note: The spinal cord (not visible) lies between the
posterior and spinolaminar lines

16. Cervical Spine Systemic Approach

17. Cervical Spine Systemic Approach
• Disc spaces - The vertebral bodies are spaced apart by the
intervertebral discs - not directly visible with X-rays. These spaces
should be approximately equal in height
Prevertebral soft tissue - Some fractures cause widening of
the prevertebral soft tissue due to prevertebral haematoma
Normal prevertebral soft tissue – narrow down to C4 and
wider below
- Above C4 ≤ 1/3rd vertebral body width
- Below C4 ≤ 100% vertebral body width
Note: Not all C-spine fractures are accompanied by prevertebral
hematoma - lack of prevertebral soft tissue thickening should NOT be
taken as reassuring
• Edge of image - Check other visible structures ( mandible, base of
occiput etc.)

18. Cervical Spine Systemic Approach

19. Cervical Spine Systemic Approach
• Bone - The cortical outline is not always well
defined but forcing your eye around the edge of
all the bones will help you identify fractures
• C2 Bone Ring - At C2 (Axis) the lateral masses
viewed side on form a ring of corticated bone
- This ring is not complete in all subjects and
may appear as a double ring
- A fracture is sometimes seen as a step in the
ring outline

20. Cervical Spine Systemic Approach

21. Projection & imaging technique

22. Cervical spine view
 AP lower cervical
AP open mouth
Lateral
Right and left oblique ( anterior or posterior)
Lateral – Flexion or Extension
Swimmer’s lateral

23. AP Projection
• Positioning:
– Patient - either erect or supine
– Center the mid-sagittal plane of
patients body to mid line of
table.
– Adjust the shoulders to lie in the
transverse plane
– Extend the neck enough so that a
line from lower edge of chin to
the base of the occiput is
perpendicular to the film.
– Central beam is directed
towards C4 VERTBRA(thyroid
cartilage)
– Tube tilt- 15 to 20 degrees
cephalad.

24. • Film size – 8x10 inches [18*22cm or 24*30cm].
• Kvp-80
• Suspended expiration.
• Collimation-include the lower margin of mandible
to lung apex.

25. AP View
• The height of the cervical
vertebral bodies should be
approximately equal.
• The height of each joint space
should be roughly equal at all
levels.
• Spinous process should be in
midline and in good
alignment.

26. LATERAL PROJECTION
(grandy method)
Patient position:
• Place the patient in a lateral position either
seated or standing
• Adjust the height of the cassette so that it is
centered at the level of 4th cervical segment
• Adjust the body in a true lateral position, with
the long axis of cervical vertebrae parallel with
plane of film
 Elevate the chin slightly to prevent
superimposition of mandible
• Ask the patient to look steadily at one spot on
the wall
• Respiration is suspended at end of full
exhalation to obtain max depression of the
shoulder

27. Lateral view.
1) Anterior arch of atlas
2) Posterior arch of atlas
3) Dens
4)Laminae C2
5) Spinous Process C6
6) C7-T1
Intervertebral
Foramina
7) Retropharyngeal
Space (Normal < 7mm)
8) Retrotracheal Space
(Normal <2cm).

29. Interpretation of Lateral View

30. • Disc spaces should be
equal and symmetric

31. AD interval
• Atlas-dens space –
should be 3mm or
less(Adult)
• 1-5mm (children)

32. • Prevertebral soft tissue
• C1 –nasopharyngeal
space-<10mm
• C2-c4 retropharyngeal
space-<5-7mm
• C5-c7- retrotracheal
space-
<14mm(children),
<22mm(adults).

33. Hyperflexion & hyperextension views
• Used to demonstrate normal antero posterior movement ,
fracture/subluxation or degenerative disc disease and often
before surgery to assess movement in the neck for
insertion of an endotracheal tube
• Spinous process are elevated and widely separated in hyperflexion.
• Depressed and closed approximation on the hyperextension
position.

34. HYPERFLEXION HYPEREXTENSION

35. ODONTOID VIEW(Fuch’s view)
• supine or erect position
• arms by the side
• open mouth as wide as possible.
• adjust head so that line from lower edge of upper incisors
to the tip of mastoid process is perpendicular to the film
• ask to phonate ah!!!!!!!!!!

36. Transoral/AP dens(peg) view
• An adequate film should include the entire
odontoid and the lateral borders of C1-C2.
• Occipital condyles should line up with the
lateral masses and superior articular facet of
C1.
• The distance from the dens to the lateral
masses of C1 should be equal bilaterally.
• The tips of lateral mass of C1 should line up
with the lateral margins of the superior
articular facet of C2.
• The odontoid should have uninterrupted
cortical margins blending with the body of C2.

38. oblique(ant.&posterior)
• Patient may be erect or
recumbent
• Patient is rotated 45 degree
to one side –to left for
demonstrating right side
neural foramina & to the
right to demonstrate left
neural foramina
• Central beam directed to c6
Vertebra (base of neck)
• Tilt of 15-20 degree caudal
for anterior oblique&
posterior oblique 15-20
degree cephalad
angulation
.

39. Lateral Swimmer’s view
Supplemental view to look especially for C7-T1 level as this site is more
susceptible to injury and is difficult to assess in basic views
The arm nearest the cassette is folded over the head
The arm and shoulder nearest the X-ray tube are depressed as far as possible

40. Lines & angle

41. Lines in cervical spine

42. Chamberlain line
Posterior margin of hard
palate to posterior
margin of foramen
magnum(opisthion)
The odontoid process
should not project
above this line more
than 3mm
It helps to recognise
basilar invagination

43. Mc Gregor line
Line is drawn from
posterosuperior margin of
the hard plate to most
caudal part of the
occipital curve of the
skull
Tip of odontoid
normally doesn’t
extend more than
4.5mm above this line

44. Mc Rae line
Line connects the basion
with opisthion of
foramen magnum
Odontoid process should
be just below this line
or the line may intersect
only at the tip of
odontoid process.

45. Ranawat method
Coronal axis of c1 is determined
by connecting centre of the
anterior arch of c1 vertebra
with its posterior ring.
Centre of sclerotic ring in
c2,represent pedicle, is
marked
Line drawn along the axis of
odontoid process to first line.
Normal distance between c1-c2
men-17mm women-
15mm(+/- 2SD)
Decrease in distance indicate
cephalad migration of c2.

46. - identifies anterior subluxation & is described as ratio of
BC/OA
- BC is the distance from the basion to the midvertical
portion of posterior laminar line of the atlas;
- OA is distance from opisthion to midvertical portion
of posterior surface of anterior ring of Atlas;
- if this ratio is greater than 1, anterior subluxation
exists;
POWERS RATIO

47. Plain film and CT demonstration of measuring
the Powers ratio. If the Power's Rule (BC)/(AO)
is greater than 1 then anterior occipitoatlantal
dislocation has likely occurred

48. HARRIS LINES
 Have also been referred to as the BDI/BAI or the Rule of
Twelve
 The basion-posterior axial line interval (BAI) is drawn along
the posterior aspect of the dens (the posterior axial line) and
a measurement between this line and the tip of the basion is
performed
 The basion-dental interval (BDI) is the distance measured
between the tip of the basion and the tip of the dens
When the the BDI and BAI to be greater than 12 mm then
occipitoatlantal dissociations has occurred
It is believed to be the useful, sensitive,radiographic
parameters for detecting and characterizing
occipitocervical dissociation

49. Sagittal CT images: Left measures the basion-posterior axial line interval which is denoted by
the small horizontal red line. The right image demonstrates measurement of the basion-
dental interval which is denoted by the vertical red line. If either of these distances are
greater than 12 mm then the diagnosis of occipitocervical dislocation is fairly certain.

50. Wachenheim clivus line
• A line drawn along
posterior aspect of
clivus towards odontoid
process
• Abnormality is
suspected when this
line does not intersect
or is tangential to
odontoid process. Eg in
basilar invagination,
atlanto-axial and
occipito- atlantal
dislocation

51.  Description: Disruption of the
atlanto-occipital junction involving
the atlanto-occipital articulations.
Mechanism: Hyperflexion or
hyperextension.
Radiographic features:
1.Malposition of occipital condyles in
relation to the superior articulating
facets of the atlas.
2.Cervicocranial prevertebral soft
tissue swelling.
Stability: unstable
ATLANTO OCCIPITAL DISLOCATION

52. Atlanto-axial dislocation
• AD interval –distance between
anterior surface of dens &
posterior surface of anterior
arch of c1.
• Atlanto axial instability is
define as increase AD interval
of >3mm (adult)
&>5mm(children).
• Symptoms presents when the
atlas moves forward on the
axis to narrow the spinal
canal & impinge on the
spinal cord.
• Almost all atlanto-axial
dislocation involve forward
movement of c1 on c2;
posterior dislocation is rare.

53. Common fractures

54. Jefferson Fracture
• Description: compression fracture of the bony ring of C1, characterized by
lateral masses splitting and transverse ligament tear
• Mechanism: axial blow to the vertex of the head (e.g. diving injury)
• Radiographic features: in open mouth view, the lateral masses of C1 are
beyond the body of C2. A lateral displacement of >2mm or unilateral
displacement may be indicative of a C1 fracture. CT is required to define
extent of fracture
• Stability: unstable

55. Jefferson fracture
A Jefferson fracture is a bone fracture occurring at the first vertebrae. It is
classically described as a four-part break that fractures the anterior and posterior
arches of the vertebra, though it may also appear as a three or two part fracture.

56. Odontoid Fractures
• Three types:
– Type I - fracture in the superior tip of the odontoid (rare)
– Type II - fracture is at the base of the odontoid. It is the most common
type of odontoid fracture and is UNSTABLE
– Type III - fracture through the body of the axis. Has the best prognosis

58. Hangman’s Fracture
• Description: fractures through the pedicle of the axis.
• Mechanism: hyperextension (e.g. hanging, chin hits dashboard in MVA)
• Radiographic feature: best seen on lateral view
– prevertebral swelling
– Anterior dislocation of the C2 vertebral body
– bilateral C2 pedicle fractures

59. • Type 1-fracture
through the pedicle of
c2.
• Type 2-
type1+concomitant
disruption of
intervertebral disc c2-
c3.
• Type 3-type2+c2-c3
facet dislocation.

60. Flexion Teardrop Fracture
• Description: posterior ligament disruption and anterior compression fracture
of the vertebral body.
• Mechanism: hyperflexion and compression (e.g. diving into shallow water)
• Radiographic feature: Teardrop fragment from anterior vertebral body,
posterior body sublux into spinal canal

62. Anterior Subluxation
• Description: disruption of the posterior ligamentous complex. Difficult to
diagnose. Subluxation may be stable initially, but it associates with 20-50%
delayed instability.
• Mechanism: hyperflexion
• Radiographic feature: best seen on flex/ext
– anterior sublux of more than 4mm
– fanning of interspinous ligaments
– loss of normal lordosis

63. Clay Shoveler’s Fracture
• Description: fracture of a spinous process C6-T1.
• Mechanism: powerful hyperflexion, usually combined with contraction of
paraspinal muscles pulling on the spinous process.
• Radiographic feature: best seen on lateral
– spinous process fracture
– ghost sign on AP (i.e.. Double spinous process of C6 or C7 resulting from
displaced fractured process)

64. Oblique fracture of lower cervical spinous process

65. Burst Fracture
• Description: fracture of C3-C7 that results from axial compression.
Injury to the spinal cord, secondary to displacement of posterior
fragments, is common. CT is required to define extent of injury
• Mechanism: axial compression
• Radiographic features: best seen on CT

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