X ray c-spine

X ray c-spine by Dr. Sulav Pradhan

1. Radiographic Anatomy And Positioning of C e r vi c a l S pine Dr Sulav Pradhan Resident (first year) Dep artment 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

6. A tl as Doesn’t Have body &spinous P rocess 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

7. Attachments Anterior tubercle & lower border of the anterior arch give attachment to ant. Longitudinal ligament. Upper border of anterior arch gives attachment to ant. Atlanto-occipital membrane. Upper surface of posterior arch has a groove- occupied by vertebral artery & first cervical nerve. Behind the groove the upper border of posterior arch give attachment to post. Atlanto-occipital membrane Lower border of posterior arch – highest pair of ligamenta flava. Posterior tubercle provide attachment to ligamentum nuchae Tubercle on medial side of the lateral mass –give attachment to transverse lig.of atlas.

8. AXIS 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. Dens provide attachment at its apex to apical ligament & on each side to alar ligament. Anterior surface of body gives attachment to ant. Longitudinal ligament. Posterior surface of body gives attachment to vertical limb of cruciate ligament , membrana tectoria , post.longitudinal ligament tectoria, post.longitudinal ligament.

10. 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

11. 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. Ossifi ca tion ce n t r es o f a tlas 3 primary ossification centre : One for anterior arch &two for neural arch Anterior ossification centre appear 20% at birth & visible by 1 year Neural arch appear at 7 th fetal week & fuse with anterior arch at 7 th year Neural arch fuse posteriorly by 3th year of life

14. Ossification centres of Axis a xis 4 ossification centre : One for each neural arch, body & odontoid process each one Odontoid process forms in utero from 2 separate ossification centre & fuse in mid line by 7 th fetal month Secondary ossification centre appear at apex of odontoid process between 3 to 6 yrs & fuse by 12-13 yrs Body fuse with odontoid process by 3-6yrs Neural arch fuse with body of odontoid between 3-6 yrs & fuse posteriorly 2-3yrs

15. Ossification of c3-c7 3 ossification centre s: 1 for body & 2 neural arch Body fuse with neural arch by 3-6yrs Neural arch fuse posteriorly by 2-3yrs Secondary ossification centre may be seen at the tip of transverse process/spinous process and persist until early 3th decade of life & stimulate fracture

16. 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

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

18. 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

19. Cervical Spine Systemic Approach

20. 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.)

21. Cervical Spine Systemic Approach

22. 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

23. Cervical Spine Systemic Approach

24. Projection & imaging technique

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

26. 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.

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

28. AP V i e w 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.

29. 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 4 th 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

30. Lateral view. Anterior arch of atlas Posterior arch of atlas Dens 4)Laminae C2 Spinous Process C6 C7-T1 Intervertebral Foramina Retropharyngeal Space (Normal < 7mm) Retrotracheal Space ( No rma l <2 c m).

31. Interpretation of Lateral View

32. Disc spaces should be equal and symmetric

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

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

35. Hyperflexion & hyperextension views Used to d emonstrate normal antero posterior movement , fracture/subluxation or degenerative disc diseas e 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.

36. HYPERFLEXION HYPEREXTENSION

37. 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!!!!!!!!!!

38. 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.

39. 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 V ertebra ( base of neck ) Tilt of 15-20 degree caudal for anterior oblique& posterior oblique 15-20 degree cephalad angulatio n .

40. 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

41. Lines & angle

42. Lines in cervical spine

43. Chamberlain line Posterior margin of hard palate to posterior ma r gin o f f o r am e n magnum(opisthion ) The odontoid process should not project above this line more than 3mm It helps to recognise basilar invagination

44. 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 do es n’t extend more than 4.5mm above this line

45. 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.

46. 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 marke d Line drawn along the axis of odontoid process to first line. Normal distance between c1-c2 me n- 17mm w o m en - 15m m (+ / - 2SD) Decrease in distance indicate cephalad migration of c2.

47. 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

48. 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

49. 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 T he 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 b e lie v ed t o b e the us e fu l , se n siti v e, r adiog r ap hic parameters for detecting and characterizing occipitocervical dissociation

50. 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.

51. 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

52. Normal variant

53. OSSICULUM TERMINALE PERSISTENUM

54. ALSO CALLED UNUNITED SUMMIT EPIPHYSIS, BERGMANN OSSICLE SECONDARY OSSIFICATION CENTRE APPEARS AT 2yrs & FUSION OCCURS BY 12-13yrs C/F: ASYMPOMATIC , BRAIN STEM FEATURES OCCURS WHEN TRANSVERSE LIGAMENTT DISLOCATES INTO THE CLEFT INCREASED INCIDENCE IN DOWN SYNDROME V SHAPED CRESENT 3-5 mm , OVOID , DIAMOND SHAPE

55. OS ODONTOIDEUM

56. ALSO CALLED UN UNITED ODONTOID PROCESS IT’S A NON-UNION OF DENS WITH AXIS BODY 3-6yrs NORMAL OSSIFICATION ASSOCIATED WITH DOWN SYNDROME, ATLAS HYPOPLASIA, KLIPPEL-FIEL SYNDROME, SKELETAL DYSPLASIA AUDIBLE CREPITUS, SUBOCCIPITAL PAIN R/F: ALTERED SHAPE OF ANTERIOR ARCH OF ATLAS (HYPERTROPHY) , ADI IS NORMAL,

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

58. 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.

59. Common fractures

60. 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

61. 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.

62. 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

63. 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

64. 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.

65. 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

66. 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

67. 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)