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Spine and Pelvis

28 Cervical Spine

Anatomy & Pathology

Anatomy and Key Landmarks

  • Vertebral body
  • Vertebral arch (pedicles, laminae)
  • Vertebral foramen and canal
  • Spinous process
  • Transverse processes with transverse foramina
  • Superior and inferior articular processes
  • Zygapophyseal (facet) joints
  • Intervertebral disks (annulus fibrosus, nucleus pulposus)
  • Intervertebral foramina
  • Atlas (C1): anterior arch, posterior arch, lateral masses
  • Axis (C2): dens (odontoid)
  • Articular pillar (lateral mass region C2–C7)
  • C7 vertebra prominens

Common Pathology 

  • Whiplash strain and degenerative changes
  • Herniated nucleus pulposus (HNP)
  • Foraminal stenosis and radiculopathy
  • Jefferson (C1 burst) and odontoid fractures
  • Subluxations
  • Cervical ribs and congenital variants

Projections

AP Axial Cervical Spine

CR Location & Positioning

  • SID: 40 inches (102 cm) or department standard
  • Patient position: Supine or upright AP with shoulders level; midsagittal plane centered
  • Adjustments: Elevate/protrude chin so occlusal plane is roughly perpendicular to IR; avoid mandibular overlap of mid-cervicals
  • CR: 15–20° cephalad to C4 (at or just below thyroid cartilage), centered midline
  • Pt. Instructions: Suspend breathing; don’t swallow
  • Exposure: Short exposure time; grid/DR per protocol

Evaluation Criteria

  • Coverage: C3 through at least T2 visible with surrounding soft tissues included
  • Rotation checks: Spinous processes midline; SC joints equidistant to spine; mandibular angles symmetric
  • Motion checks: Sharp cortical margins and trabeculae; airway edges distinct
  • Technique checks: Open intervertebral disk spaces from cephalic angle; adequate penetration through shoulders; no saturation
  • Clinical aim: Survey vertebral bodies, disk spaces, hardware, or cervical ribs as applicable

AP Open-Mouth (Odontoid)

CR Location & Positioning

  • SID: 30–40 inches per department protocol
  • Patient position: Supine or upright; mouth wide open
  • Adjustments: Align lower margin of upper incisors with mastoid tips so occlusal plane is perpendicular to IR; slight head tilt as needed
  • CR: Perpendicular through open mouth to midline at C1–C2
  • Pt. Instructions: Keep mouth open; softly say “ah” to depress tongue; suspend breathing
  • Exposure: Short exposure; tight collimation

Evaluation Criteria

  • Coverage: Dens, C1 lateral masses, and C2 body included; atlantoaxial joints visible
  • Rotation checks: Mandibular rami equidistant from dens; lateral masses symmetric
  • Motion checks: No motion of jaw or tongue; crisp dentition and dens margins
  • Technique checks: Tongue not over C1–C2; no incisors or skull base superimposing dens
  • Clinical aim: Assess dens integrity and C1–C2 alignment

AP Dens (Fuchs)

CR Location & Positioning

  • SID: 40 inches
  • Patient position: Supine (non-trauma only)
  • Adjustments: Elevate chin so line from tip of chin to mastoid tips is vertical; MSP perpendicular
  • CR: Perpendicular just distal to chin, centered midline to level of mastoid tips
  • Pt. Instructions: Suspend breathing; hold still
  • Exposure: Short exposure; tight collimation

Evaluation Criteria

  • Coverage: Entire dens within foramen magnum
  • Rotation checks: Mandible and cranium symmetric about dens
  • Motion checks: Sharp dens margins
  • Technique checks: Adequate contrast to see cortical outline within foramen
  • Clinical aim: Alternative dens visualization when open-mouth view is inadequate

Lateral Cervical Spine (Grandy)

CR Location & Positioning

  • SID: 60–72 inches
  • Patient position: True lateral, seated or standing, shoulder against detector
  • Adjustments: Depress shoulders (equal weights if safe); elevate chin slightly or protrude mandible to clear C1–C2; MSP vertical
  • CR: Horizontal, perpendicular to C4; top of IR about 1 inch above EAM
  • Pt. Instructions: Suspend on full expiration to lower shoulders; hold still
  • Exposure: Short time; grid or high kVp per protocol

Evaluation Criteria

  • Coverage: C1 through at least C7 and ideally T1; prevertebral soft tissues included
  • Rotation checks: Zygapophyseal joints superimposed; articular pillars aligned; mandibular rami nearly superimposed
  • Motion checks: Sharp endplates and spinous tips; no swallow blur
  • Technique checks: Open disk spaces; adequate penetration through shoulders; visible soft tissue detail
  • Clinical aim: Evaluate alignment, disk height, facet relationships, and prevertebral swelling

Cervicothoracic Lateral (Swimmer’s)

CR Location & Positioning

  • SID: 60–72 inches
  • Patient position: Lateral (upright preferred or recumbent)
  • Adjustments: Raise arm closest to IR overhead; depress opposite shoulder; MSP parallel; head neutral lateral
  • CR: Perpendicular to C7–T1 (2 inches above jugular notch); 3–5° caudal if shoulder can’t depress
  • Pt. Instructions: Suspend breathing; minimize motion
  • Exposure: Consider breathing technique only if immobilized; use compensating filter if available

Evaluation Criteria

  • Coverage: C5–T3 region with C7–T1 clearly demonstrated
  • Rotation checks: Humeral heads offset (one anterior, one posterior) with minimal superimposition on spine
  • Motion checks: Sharp vertebral margins despite shoulder thickness
  • Technique checks: Sufficient penetration to see vertebrae between shoulders; good soft tissue detail
  • Clinical aim: Visualize C7/T1 when standard lateral is inadequate

Posterior Obliques (RPO/LPO) – AP Axial Obliques

CR Location & Positioning

  • SID: 60–72 inches
  • Patient position: Upright preferred; posterior oblique 45° with shoulder against IR
  • Adjustments: Keep head aligned at same 45° as torso; elevate/protrude chin to clear upper spine without rotating superior vertebrae
  • CR: 15–20° cephalad to C4; center to spine
  • Pt. Instructions: Suspend breathing; hold still
  • Exposure: Short exposure; tight collimation

Evaluation Criteria

  • Coverage: C2–C7 intervertebral foramina and pedicles
  • Rotation checks: Foramina “side up” open and uniform; pedicles of elevated side in profile
  • Motion checks: Crisp foraminal walls; no swallow blur
  • Technique checks: Open disk spaces; occiput and mandible not obscuring C1–C2
  • Clinical aim: Demonstrate intervertebral foramina on the elevated side

Anterior Obliques (RAO/LAO) – PA Axial Obliques

CR Location & Positioning

  • SID: 60–72 inches
  • Patient position: Upright preferred; anterior oblique 45°
  • Adjustments: Chin elevated/protruded to clear upper spine; align head with torso (avoid extra head turn)
  • CR: 15–20° caudad to C4; center to spine
  • Pt. Instructions: Suspend breathing
  • Exposure: Short exposure; tight collimation

Evaluation Criteria

  • Coverage: C2–C7 intervertebral foramina and pedicles
  • Rotation checks: Foramina “side down” open and uniform; pedicles of dependent side in profile
  • Motion checks: Sharp foraminal margins
  • Technique checks: Open disk spaces; no mandibular or occipital superimposition on C1–C2
  • Clinical aim: Demonstrate intervertebral foramina on the dependent side

Lateral Flexion and Extension (Functional)

CR Location & Positioning

  • SID: 60–72 inches
  • Patient position: True lateral upright
  • Adjustments: Flexion—tuck chin toward chest; Extension—elevate chin and look slightly up; keep shoulders depressed and in same plane
  • CR: Horizontal to C4
  • Pt. Instructions: Suspend breathing; move only head/neck as directed
  • Exposure: Short time; obtain only after stability is cleared per protocol

Evaluation Criteria

  • Coverage: C1–C7 included on both positions
  • Rotation checks: Articular pillars aligned; true lateral maintained in both views
  • Motion checks: Clear spinous processes; no swallow blur
  • Technique checks: Distinct disk spaces; interspinous spacing widens in flexion and narrows in extension
  • Clinical aim: Assess cervical stability and motion limits.

Hows & Whys of Cervical Spine Radiography

Anatomy

  • Which unique features distinguish typical cervical vertebrae from other regions?
    Transverse foramina for vertebral vessels and bifid spinous tips, with prominent articular pillars.
  • What motion occurs primarily at the atlanto-occipital and atlanto-axial joints?
    Atlanto-occipital flexion/extension (“yes”) and atlanto-axial rotation around the dens (“no”).
  • Why is C7 called vertebra prominens?
    Its long nearly horizontal spinous process is easily palpable posteriorly.

Positioning 

  • Why use a 15–20° cephalic angle on the AP axial?
    To align the beam with inferiorly tilted cervical disk spaces so they open on the image.
  • Why elevate or protrude the chin on AP axial and lateral views?
    To keep the mandible from obscuring C1–C2 and the upper cervical bodies.
  • Why use 60–72 inch SID for lateral and obliques?
    To decrease magnification from OID and better include C7.
  • Why depress the shoulders on the lateral?
    To reveal C7/T1 without additional beam angulation.
  • Why rotate 45° and angle the CR 15–20° on obliques?
    Because cervical foramina open 45° to the MSP and tilt about 15° inferiorly.
  • Why align the occlusal plane and keep the mouth open for the odontoid?
    To clear the dens of teeth and skull base while dropping the tongue inferiorly.
  • Why choose the Fuchs method when the open-mouth fails?
    Hyperextension projects the dens within the foramen magnum, bypassing dental/skull-base overlap.
  • Why raise the near arm and depress the far shoulder for Swimmer’s?
    To separate humeral heads and clear the C7–T1 junction.

Technique & Image Evaluation

  • How can you tell the cephalic angle was correct on AP axial?
    Intervertebral disk spaces are open and spinous processes stay midline.
  • How can you tell chin position was correct on AP axial?
    Mandible and occiput overlay only C1–C2, not mid-cervicals.
  • How can you tell the lateral is truly lateral?
    Zygapophyseal joints and articular pillars are superimposed and mandibular rami nearly overlap.
  • How can you tell you included C7/T1?
    C7 and the C7–T1 interspace are visible; otherwise a Swimmer’s is needed.
  • How can you tell obliques are correctly rotated and angled?
    Target-side foramina are uniformly open from C2/3 to C7/T1 with the corresponding pedicles in profile.
  • How can you tell the odontoid view is aligned?
    Dens and lateral masses are symmetric; no teeth or skull base over the dens; no tongue shadow on C1–C2.
  • How can you tell Fuchs succeeded?
    The dens lies entirely within the foramen magnum with symmetric margins.
  • How can you tell functional laterals are adequate?
    All seven vertebrae are included; spinous processes separate in flexion and approximate in extension without rotation change.

Clinical Applications

  • What projection is obtained first in acute trauma?
    Cross-table lateral to assess alignment and prevertebral soft tissues before additional views.
  • When pick posterior versus anterior obliques?
    Posterior obliques show “side up” foramina; anterior obliques show “side down” and may reduce thyroid dose due to PA orientation.
  • When is Swimmer’s required?
    When C7/T1 is not visible on the standard lateral due to shoulder superimposition.
  • If you want me to convert any sections into a mobile-optimized quick chart (same Pressbooks-friendly lines), I can add that at the end.

 

License

Radiographic Procedures Review Guide Copyright © 2025 by Carla M. Allen and Taylor M. Otto. All Rights Reserved.

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