X-ray cervical spine

Dr RajaResidentDept. of radiodiagnosis

Topics to be discussed

• Anatomy• Projection techniques• Lines and angles of spine• Normal variants of spine• Common fractures

Anatomy of cervical spine

Cervical vertebrae

2 TYPES– Atypical• Axis• Atlas• C 7

– Typical• C 3-6

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 condoyle- atlanto-occipital joint.

• Inferior articular facet articulate with axis superior facet –atlanto-axis joint.

• Transverse process project laterally from lateral mass which is pierced by foramen transversorium

Attachment• 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.

AXIS

• The second cervical vertebra (C2) of the spine is named

the axis • The most distinctive

characteristic of this bone is the strong

odontoid process ("dens") which rises perpendicularly from the upper surface of the body

• 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.

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 ligaments– Limit flexion and rotation/limits lateral

flexion• Ligamentum flavum

– Attach lamina of one vertebrae to another, reinforces articular facets

– Limits flexion and rotation

Ossification centres of atlas• C1-3 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 7th fetal week & fuse with anterior arch at 7th year

• Neural arch fuse posteriorly by 3th year of life.

Ossification centres of axis• C2-4 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 7th 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.

C3-c6 vertebra• The body of these four vertebrae is small, and broader

from side to side than from front to back.

• The pedicles are directed laterally and backward, and are attached to the body midway between its upper and lower borders, so that the superior vertebral notch is as deep as the inferior.

• The laminae are narrow, and thinner above than below; the vertebral foramen is large, and of a triangular form.

• The spinous process is short and bifid, the two divisions being often of unequal size.

• The superior and inferior articular processes of neighbouring vertebrae often fuse on either or both sides to form an articular pillar, a column of bone which projects laterally from the junction of the pedicle and lamina.

• The transverse processes are each pierced by the foramen transversorium, which, in the upper six vertebrae, gives passage to the vertebral artery and vein, as well as a plexus of sympathetic nerves. Each process consists of an anterior and a posterior tubercle. These two parts are joined, outside the foramen.

Cervical Vertebra (C7)

• .Its has a long and prominent spinous process. Its thick, nearly horizontal, not bifurcated.Foramen transversorium may be as large as that in the other cervical vertebrae

On the left side it occasionally gives passage to the vertebral artery; more frequently the vertebral vein transverses it on both sides; but the usual arrangement is for both artery and vein to pass in front of the transverse process, and not through the foramen.

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.

Ossification of c3-c7• 3 ossification centre-one

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.

• Spinal Nerves– C1-c8– Cervical Plexus

• C1-C4• C4 -Phrenic Nerve - Breathing

– Brachial Plexus• C5-T1

C3

Dermatomes

Myotomes C5 – Abduction

C6 – Elbow Flexion/Wrist Extension

C7 – Elbow Extension/Wrist Flexion

C8 – Finger Flexion

C1-2 – Neck Flexion

C3 – Lateral Neck Flexion

C4 – Shoulder Elevation

C1 – top of head

C2 – Temporal

C3 – Side of jaw/neck

C4 – top of shoulders

Brachial Plexus

Projection & imaging technique

Cervical spine view

Plain Films

• Plain films provide the quickest way to survey the cervical spine. An Adequate spine series includes three views: a true lateral (which must include all seven cervical vertebrae as well as C7-T1 junction), and AP view, and an open mouth odontoid view. These three views do not require the patient to move the neck, and should be obtained without removal of the cervical collar.

POSITIONING• AP projection :

– 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.

• Film size-18*22cm or 24*30cm.• Kvp-80• Suspended expiration.• Collimation-include the lower margin of mandible to

lung apex.

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.

• Progressive loss of disc height uncinate process impact on the reciprocating fossa,producing osteophytes

• Spinous process should be in midline and in good alignment.

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 too look steadily at one spot on the wall to aid in maintaining the position of head

• Respiration is suspended at end of full exhalation to obtain max depression of the shoulder.

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).

Interpretation of Lateral View

• Disc spaces should be equal and symmetric

AD interval

• Atlas-dens space – should be 3mm or less(Adult)

• 1-5mm (children)

• Prevertebral soft tissue• C1 –nasopharyngeal

space-<10mm• C2-c4 retropharyngeal

space-<5-7mm• C5-c7- retrotracheal

space-<14mm(children), <22mm(adults).

Hyperflexion & hyperextension views• Used to Demonstrate normal anterioposterior movement or

fracture/subluxation or degenerative disc disease(vacuum phenomenon).

• Spinous process are elevated and widely separated in hyperflexion.• Depressed and closed approximation on the hyperextension

position.

HYPERFLEXION HYPEREXTENSION

ODONTOID 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!!!!!!!!!!

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.

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.

job list

• NAME,AGE, SEX• IP NO, INDICATION• CONTOUR • ALIGNMENT• DENSITY• IVDS• LINES• BONES• JOINTS• PRE AND PARAVERTEBRAL SOFT TISSUE

Lines & angle

Lines in cervical spine

Chamberlain linePosterior margin of hard

palate to posterior margin of foramen magnum(opisthion)

The odontoid process should not project above this line more than 3mm.

Mc Gregor lineLine is drawn from

posterosuperior margin of the hard plate to most caudal part of the occipital curve of the skull.

Tip of odontoid normally don’t extend more than 4.5mm above this line.

Mc Rae lineLine 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.

Ranawat methodCoronal 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.

- 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

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

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 .

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.

• 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.

Normal variant

OSSICULUM TERMINALE PERSISTENUM

• ALSO CALLED UNUNITED SUMMIT EPIPHYSIS, BERGMANN OSSICLE

• SECONDARY OSSIFICATION CENTRE APPEARS AT 2yrs & FUSION OCCURS BY 12-13 yrs

• 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

OS ODONTOIDEUM

• 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,

ATLANTO OCCIPITAL DISLOCATION

• 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-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.

• Traumatic –motor vehicle accident.• Non-traumatic cause-down’s syndrome,grisel

syndrome,morquio syndrome,rheumatoid arthritis,osteogenesis imperfecta

Common fractures

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

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.

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.

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

• 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.

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

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

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)

Oblique fracture of lower cervical spinous process

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

Unilateral Facet Dislocation• Description: facet joint dislocation and rupture of the hypophyseal joint

ligaments.• Mechanism: simultaneous flexion and rotation• Radiographic features: best seen on lateral and oblique

– Anterior dislocation of affected vertebral body by less than half of the vertebral body AP diamete

– widening of the disc space

Bilateral Facet Dislocation• Description: complete anterior dislocation of the vertebral body. It is

associated with a very high risk of cord damage.• Mechanism: extreme flexion of head and neck without axial compression• Radiographic feature: best seen on lateral

– complete anterior dislocation of affected body by half or more of the vertebral body AP diameter.

– “Bow tie” or “Bat wing” appearance of the locked/jumped facets.

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