Cervical Vertebrae Imaging Techniques Quiz

Agenda

• Course plan overview
• Discussion on clinical experience
• Lecture

Objectives

• Perform basic cervical spine projections
• Indications for cervical spine imaging
• Basic image critique

Anatomy of the Cervical Spine

• C1 (Atlas): Located at the top of the spine, forms articulation with the occipital bone, lacks spinous process and vertebral body
• Dens (Odontoid process) of C2 (Axis): Located in the anterior portion of the ring, supporting the spinal cord
• Transverse processes of C1: Are longer and sit laterally and slightly inferior
• Superior articular processes of C1: Are large and deeply concave
• Odontoid process of C2: strong and connected to the occipital bone condyles
• C3-C6 Vertebrae (Typical Vertebrae): Narrow and thin, with short and wide processes, having double-pointed tips. Their superior and inferior articular processes connect to the succeeding cervical vertebrae
• C7 (Vertebra Prominens): Has a long prominent spinous process that's easily palpable at the base of the neck. It represents a key landmark

Cervical & Lumbar Spinal Curves

• Concave posteriorly
• Lordotic curve
• Compensatory curves

Thoracic & Sacral Spinal Curves

• Convex posteriorly
• Kyphotic curve
• Primary curves

Basic Cervical Views

• AP "Open Mouth" Projection (C1-C2)
• AP Axial Projection (C3-C7)
• Lateral Projection
• Other, supplemental views, including:
  • Cervicothoracic Swimmer's Lateral Position (Twining Method)
  • Anterior & Posterior Oblique Projections
  • Lateral Projections (Flexion and Extension)
  • AP Axial Projection (Ottonello Method) - Wagging Jaw
  • AP/PA Projection for C1/C2 (Fuchs Method)

Patient Preparation

• Remove preventable artifacts (earrings, chains, hairpins, braids, wet hair, extensions, dentures, partial plates, retainers, clothing, shirts, bra straps, gum or candy)
• Specifics for pregnancy screening/childbearing age (no longer an OTIMROEMPQ requirement)

In practice...

• Lateral Projection (alignment, potential artifacts, first projection for trauma using horizontal beam lateral projection)
• AP Axial Projection
• Open Mouth Projection

Indications for Cervical Spine X-rays

• Chronic neck pain
• Acute neck pain
• Rule out fractures
• Rule out disc herniation
• Arthritis (degenerative bone/disc or joint disease)
• Limited range of motion
• Pathology (rule out metastasis, osteoporosis)
• Radiculopathy (numbness or pain in arms, hands, or fingers due to nerve root compression)
• Referred Pain (pain felt in a body part other than the source)

Useful Landmarks

• Meatus (opening leading to the inferior of the body)
• Glabelloalveolar (GAL)
• Glabellomeatal line (GML)
• Orbitomeatal line (OML)
• Infraorbitomeatal line (IOML) or Reid's base line
• Acanthiomeatal line (AML)
• Lips-meatal line (LML)
• Mentomeatal line (MML)
• Interpupillary line
• Occlusal plane

C-Spine Open Mouth C1/C2 Odontoid Projection

• Patient position: AP supine or erect, face forward, mandibular angles & mastoid tips at equal distances from the IR, tuck chin, align lower edge of upper incisors and mastoid tip perpendicular to the IR, instruct patient to open mouth widely
• Central ray: Perpendicular to IR, Angle 5 degrees cephalically, center to MSP & midpoint of open mouth, instructed to keep mouth wide open during exposure, 75+/- 5 kV range
• Purpose: Prevents mandible movement, places the tongue, and prevents it's projection on the Atlas or Axis

C-Spine Image Analysis Guidelines

• Symmetry of atlas on axis (lateral masses equal distance from dens)
• Axis spinous process aligned with axis body midline
• Mandibular ram equidistant from dens
• Odontoid (dens) centrally located in the exposure field
• Atlantoaxial joint open
• Proper collimation and marker

C-Spine Image Analysis - Rotation

• Distance between mandibular rami and lateral masses
• Side with greater distance indicates rotation direction

C-Spine Image Analysis - Angulation

• Upper incisors not aligned perpendicular to the IR
• 5° cephalic angulation needed for upper incisors
• Upward tilting instead of chin tilt, superimposed dens and atlantoaxial joints

C-Spine AP Axial Projection

• Patient position: supine or erect, face forward, mandibular angles and mastoid tips at equal distances from the IR, lower surface of upper incisors and tip of mastoid process perpendicular to the IR, align the midline of the neck with the midline of the IR and grid
• Central ray: Directed through C4 at 15-20 degrees cephalad, for supine 15 degrees, for erect 20 degrees, for kyphotic angle > 20 degrees, enter at most prominent point of thyroid cartilage (Adam's Apple), center CR to the MSP at a level halfway between the EAM and the jugular notch.
• 75 +/- 5 kV range

C-Spine Image Analysis - Lordotic Curvature

• Degree of CR angulation needed to obtain open intervertebral disk spaces and align spinous processes within them
• Supine: Gravitational pull places middle cervical vertebrae more straight
• Intervertebral spaces free of superimposition
• Correct tube angulation for a correct image

C-Spine Image Analysis - Rotation

• Mandibular angles and mastoid tips distance from the cervical vertebrae
• Spinous processes' distance from the cervical vertebrae
• Pedicles and articular pillars' lateral symmetry from the vertebral bodies
• Clavicles medial ends distance from vertebral column

C-Spine Lateral Projection

• Patient position: AP supine or erect, midcoronal plane passing through the mastoid tip centered to IR, chin elevation, align IPL perpendicular to IR, parallel chin to floor to prevent mandible superimposition on spine, depress shoulders, patient holds under chair and suspend at end of full exhalation
• Central ray: perpendicular to 1-inch distal point of the adjacent mastoid tip, SID 72 inches, 75 +/-5 kV range, if spine further from IR, 72 SID use weigh to depress shoulder for 5-10 lbs weight.

Lateral Cervical Views - Image Analysis Guidelines

• Superimposition of structures (anterior/posterior/superior/inferior aspects of right/left articular pillars, zygapophyseal joints)
• Mandibular rami in profile
• Spinous processes in profile/open intervertebral disk spaces
• Posterior C1 arch & spinous process of C2 in profile (without occipital base superimposition, and degree of chin elevation)
• C1 and C2 bodies, without mandibular superimposition
• Sella turcica, clivus, C1-C7, and half of T1 are all included in the exposure field
• Proper collimation and marker
• Positioning for separation of structures

Lateral Flexibility and Extension Views - Image Analysis

• Placement on the same horizontal plane
• If head tilted toward IR, separation between right and left articular pillars and zygapophyseal joints
• Inferior cortices of the cranium and mandibular rami are demonstrated without superimposition
• C1 vertebral foramen

Additional Views (Uncommon)

• Spread the word (additional views, often not needed as routine)

AP Projection - Fuchs' Method

• Patient position: Supine, extend the chin until the tip of the chin and mastoid process are vertical, adjust the head so the MSP is perpendicular to the plane of the grid,
• Central ray: Perpendicular to the midpoint of the IR, enter the neck on the MSP just distal to the tip of chin, 75 +/- 5 kV range
• Evaluation criteria: Entire dens lies within the foramen magnum, and no head/neck rotation (symmetrical mandible, cranium and vert.

AP Projection - Ottonello Method (Wagging Jaw)

• Patient position: Supine, elevate the chin and place the occlusal surface of the upper incisors and the mastoid tips in the same vertical plane, mandible is rigidly immobilized,
• Use low mA & long exposure time,
• Mandibular shadow is blurred by the chewing motion during exposure
• Central ray: Perpendicular to C4, enters the neck at the most prominent point of the thyroid cartilage
• Evaluation criteria: Entire cervical spine is recorded with the mandible blurred or obliterated

AP Axial Projection - Vertebral Arch (Pillars)

• Patient position: Supine, with MSP of the head perpendicular to the table; if the patient cannot extend their neck, use an oblique approach,
• Central ray: Directed at C7 at an angle of 25 degrees caudad
• Angulation determined by the cervical lordosis (more lordosis = more angle), for 75 +/- 5 kV range
• Evaluation criteria: Vertebral arch structures without overlapping of vertebral bodies & transverse process, open zygapophyseal joints between the articular processes.

Image Analysis - Trauma Unit

• First projection: horizontal beam lateral (to evaluate patient prior to any movement)
• Do not manipulate head/depress shoulders/perform swimmers view unless physician permits

C-Spine Lateral Cervicothoracic/Swimmers/Twinning Method

• Goal: Separating overlapping structures
• Indications: When C7/T1 not demonstrated on lateral cervical spine (post-op, pathology)
• Patient position: Erect or recumbent lateral position (flex knee and hip for recumbent, distribute weight on both feet for upright, position the MCP perpendicular to the IR, elevate the arm closer to the IR above the head, align opposite arm along the side and depress the shoulder, position the head in lateral position, and ensuring that IPL perpendicular to the IR and MSP parallel with the IR, CR skims shoulder, at same level of T1, increase kVp, to 80-90ish).
• Central ray: Center CR to MCP 1-inch superior to the jugular notch or prominens.SID 72 inch, and 80 +/- 5 kV range. If the patient cannot depress their shoulder use a 5-degree caudal CR angulation, Exposure occurs during suspended expiration.

Image Analysis - Cervical Rotation Detection

• Orientation of mandibular angles and mastoid tips from cervical vertebrae.
• Spinous processes distance from the cervical vertebrae.
• Lateral symmetry of pedicles and articular pillars related to vertebral bodies
• Evaluation of clavicle medial ends, from vertebral column.

Image Analysis-Obliquity

• Insufficient obliquity: Less than 45-degree obliquity will result in narrowed intervertebral foramina, obscured or foreshortened pedicles of interest.
• Excessive obliquity: Greater than 45-degree rotation - opposite pedicles positioned along the midline of the vertebral bodies. Zygapophyseal joints with demonstrated vertebral bodies without superimposition are demonstrated in profile.

Image Analysis of Kyphosis

• Excessive kyphotic curvature of thoracic vertebrae result in excessive lordotic curvature of the cervical vertebrae.
• Demonstrate cervical vertebrae with open intervertebral spaces for an upright AP axial projection, may need adjust of CR angulation above routine.

Image Analysis - Additional Observations (Uncommon Projections)

• C-spine AP and PA axial oblique projections;
• Proper patient positioning is vital - head rotated; rotated 45°, then head's MSP is aligned with the IR;
• To open the intervertebral spaces;
• Lateral view for evaluating rotation;
• The vertebral bodies will be closer or farther from the IR.

Additional Views (Uncommon)

• Spread the word (additional views, often not needed as routine)

Test your knowledge on the proper techniques for imaging cervical vertebrae. This quiz covers adjustments needed for projection angles, patient positioning, and common errors during imaging that affect results. Ensure your understanding of essential practices for cervical radiography.