RT 110+111 Unit 3: Vertebral Column Anatomy and Positioning

Overview of anatomy of vertebral column, positioning, and evaluation criteria and scenarios for spine examinations

How many sections does the vertebral column contain?

5: cervical, thoracic, lumbar, sacral, and coccygeal.

What purpose does the vertebral column serve?

Protects the spinal cord

Provides flexible support for the trunk and head

Acts as attachment sites for deep muscles of the back and ribs

The openings within each vertebrae create a tube-like opening for the spinal cord called the ___.

spinal canal

Where does the spinal cord begin? Where does it end?

Begins at the medulla oblongata

Ends at the lower border of the 1st lumbar vertebrae

Describe the structural components of the vertebral column

The vertebral column is composed of singular segments called vertebrae held together by ligaments.

What is located between each vertebrae? What purpose do they serve?

Fibrocartilaginous intervertebral disks

Allows for movement and flexibility of the vertebral column

T/F: The average adult vertebral column is composed of 33 separate bones

False

How many vertebrae are in each division of the vertebral column?

Cervical - 7

Thoracic - 12

Lumber - 5

Sacrum - 1 (3-5 fused bones)

Coccyx - 1 (3-5 fused bones)

The largest and strongest weightbearing vertebrae is the ___.

lumbar vertebrae

What terms are used to describe the curvature of the vertebral column?

Concave = rounded inward or depressed surface

Convex = rounded outward or elevated surface

Which sections of the vertebral column curve inward?

Cervical and lumbar

Which sections of the vertebral column curve outward?

Thoracic and sacral

An abnormal or exaggerated lumbar curvature or increased concavity is called ___.

lordosis

The abnormal increased convexity of the thoracic spine curvature creating a “humpback” appearance is called ____.

kyphosis

An abnormal or exaggerated lateral curvature of the spine is called ___.

scoliosis

The most superior portion of the vertebral column is the ____.

cervical spine

The small horns extending laterally from the pedicle and body are the ___.

transverse processes (F)

The bridge extending from each side of the vertebral body that forms part of the transverse foramen is the ___.

pedicle (C)

Openings on each side of the vertebrae that allow arteries, veins, and nerves to pass through are called ___.

transverse foramina (E)

Posterior bony structures extending from the lamina that form bifid tips on C3-C6 are called ___.

spinous process (H)

Circular opening between the posterior surface of the body and vertebral arch that allows the spinal cord to pass through is known as ____.

vertebral foramen (G)

What characteristics do cervical vertebrae possess that no other vertebrae have?

Bifid spinous processes on C3-C6

Articular pillars

3 foramina

Another name for C7 spinous process is ___.

vertebra prominens

The column of bone between the superior and inferior articular processes is known as ___.

articular pillar/lateral mass (C1)

The superior and inferior articular processes come together to form a joint between them that allows movement between vertebrae known as ___.

zygapophyseal joints

Zygapophyseal joints of the second through seventh cervical vertebrae can only be visualized in ____.

lateral projection

Zygapophyseal joints of the first and second cervical vertebrae (atlantoaxial) can only be visualized in ___.

AP open mouth projection

The intervertebral foramina can only be visualized radiographically ___.

45* oblique with a 15-20* cephalic angle

What makes the first cervical vertebrae different from the rest?

No anterior body, posterior laminae, or spinous process

The first cervical vertebrae (atlas) is composed of a thick arch of bone called ___, which includes a smaller tubercle.

anterior arch

The first cervical vertebrae (atlas) contains a thick posterior arch of bone called ___, which also includes a smaller tubercle instead of a spinous process.

posterior arch

Large depressed surfaces on each side of C1 that articulate with the occipital condyles are called ___.

superior articular facets

The large pillars between the superior and inferior articular processes that support the weight of the head and assist in rotation of the head are called ___.

lateral masses

The most distinctive feature of the second cervical vertebra (axis) is a conical process projecting up from the superior surface of the body called ___.

odontoid process/dens

T/F: Forced flexion-hyperextension “whiplash” injuries may fracture the dens

True

The ___ for articulation with C3 lies inferior to the lamina.

inferior articular process

T/F: The transverse process and foramina of the second cervical vertebrae lie inferior and lateral to the superior articular process

True

Which projection is used to demonstrate pathology and fractures in the mid and lower cervical spine?

AP axial cervical spine

What technical factors are used to visualize an optimal AP axial projection of the cervical spine?

40” SID, 14×17” IR portrait, collimation on both sides of jaw and top of ear, 70-85 kVp, grid, center photocell, 15-20* cephalic angle, suspend respiration

How is the patient and part positioned for an AP axial projection of the cervical spine?

Patient is erect or supine with MSP aligned to CR and midline of the table

Adjust head so that a line from the lower margin of upper incisors to mastoid processes is perpendicular to table and/or IR

Line from tip of mandible to base of skull is parallel to angled CR

Where is the CR centered for an AP axial cervical spine projection?

CR is angled 15*-20* cephalad and directed to the level of the upper margin of thyroid cartilage to pass through C4

To properly demonstrate open intervertebral disks spaces between cervical vertebrae, what must happen to the CR?

Angle 15*-20* cephalic

If a patient has a smaller lordotic curvature in their neck, the CR should be angled ___.

15* cephalic

If a patient has a greater lordotic curvature in their neck, the CR should be angled ___.

20* or more cephalic

What anatomy should be demonstrated in an AP axial projection of the cervical spine?

C3-T2 vertebral bodies, space between pedicles, open intervertebral disk spaces seen

If the mandible amd base of the skull superimpose the first two cervical vertebrae on an AP axial projection, what error occurred?

No error occurred. It fits with the evaluation criteria

How is no rotation indicated in an AP axial projection of the cervical spine?

Spinous processes and sternoclavicular joints (if visible) are equidistant from the spinal column lateral borders

Which projection best demonstrates the odontoid process and C1 and C2 structures?

AP open mouth

What technical factors are used on an AP open mouth projection?

40” SID, small collimation from cheek to cheek, 14×17” IR portrait, grid, 70-85 kVp, no AEC, suspend respiration

How is the patient and part positioned for an AP open mouth?

Patient is erect or spine with their MSP aligned to CR and midline of table

Adjust head so that, with mouth open, a line from the lower margin of upper incisors to the base of the skull is perpendicular to the table and/or IR

No rotation of the head

Ensure the mouth is open wide, only have the lower jaw drop

Where is the CR centered for an AP open mouth?

CR is directed through the center of open mouth

What anatomy should be demonstrated in an AP open mouth?

Odontoid process (dens) and vertebral body of C2, lateral masses and transverse processes of C1, and atlantoaxial joints

If the teeth are superimposed on the upper dens, what positioning error occurred?

Insufficient extension of the neck

Fix: slightly tilt head back (extend) or angle CR slightly cephalic (up)

An AP open mouth projection was taken and the image shows the odontoid process being superimposed by the base of the skull. What positioning error occurred? If an error occurred, how should it be fixed?

Insufficient flexion of the neck

Fix: Tilt the head down or angle slightly caudal

How is no rotation indicated in an AP open mouth?

Equal distances from lateral masses and/or transverse processes of C1 to condyles of mandible

Center alignment of spinous processes of C2

If the upper odontoid process cannot be demonstrated with an AP open mouth, what other projections are used?

Fuchs or Judd methods

What technical factors are used for Fuchs (AP) and Judd (PA) method?

40” SID, small collimation from chin to middle of throat or midoccipital lobe, grid, 70-85 kVp, no AEC, suspend respiration

How is a patient and part positioned for an AP projection of the dens Fuchs method?

Patient is erect or supine

Chin is elevated as needed to bring the MML near perpendicular to tabletop

No rotation of the head

Where is the CR centered for an AP projection of the dens Fuchs method?

CR is parallel to MML, directed 1” below mastoid tips and mandible angles

How is a patient and part positioned for a PA projection of the dens Judd method?

Patient is erect or supine

Chin is resting on Bucky or tabletop and extended to bring MML near perpendicular to IR

No rotation of the head

Where is the CR centered for a PA projection of the dens Judd method?

CR is parallel to MML through midoccipital bone, about 1” below mastoid tips and mandible angles

What anatomy should be demonstrated in AP/PA projections of the dens Fuchs/Judd methods?

Dens is centered within the foramen magnum

Dens is free of superimposition from the mandible

How is no rotation indicated in an AP/PA projection of the dens (Fuchs/Judd methods)?

Symmetric appearance of the mandible arched over foramen magnum

Why is AEC not recommended for AP open mouth, Fuchs, and Judds?

The odontoid has a smaller field of view

If trauma is present, should the Fuchs or Judd method projections be performed? Why or why not?

No because it could further injure the patient's neck