c spine positioning quiz

Size of collimated field for AP Dens (Fuchs Method)

5×5 inches

Key patient positioning points for AP Dens (Fuchs Method)

• supine

• Msp of head perpendicular to IR

• chin extended/ place tip vertical

Anatomic landmarks and relation to IR for AP Dens (Fuchs Method)

Mastoid tip and tip of chin aligned and perpendicular to IR

CR orientation and entrance point for AP Dens (Fuchs Method)

CR perpendicular to MSP just distal to tip of chin

Size of collimated field for AP atlas and axis open mouth

5×5 inches

Key patient/ part positioning points for AP atlas and axis open mouth

• supine

• Msp of head perpendicular

• Mouth open

Anatomic landmarks and relation to IR for AP atlas and axis open mouth

Mastoid tip and lower edge of upper incisors align perpendicular to IR

CR orientation and entrance point for AP atlas and axis open mouth

CR entering midpoint of open mouth

Size of collimated field for AP Axial

10×12 inches and 1 inch beyond skin shadow on each side

Key patient/ part positioning points for AP Axial

• supine or upright

• Msp of head perpendicular

• Chin elevated to place occlusal plane perpendicular to IR

Anatomic landmarks and relation to IR for AP Axial

C4 centered to IR

CR orientation and entrance point for AP Axial

Angled 15-20 degrees cephalad entering C4

Size of collimated field for lateral (grandy) method

10×12 inches

Key patient/ positioning points for lateral (grandy) method

• upright lateral

• Msp perpendicular to IR

• Chin elevated slightly

• Head in a true lateral position

• IP lines perpendicular

Anatomic landmarks and relation to IR for lateral (grandy) method

• IR centered to C4

• Mcp perpendicular to IR

CR orientation and entrance point for lateral (grandy) method

CR perpendicular to IR

Size of collimated field for AP axial oblique

10×12 inches

Key patient/ positioning points for AP axial oblique

• Upright or recumbent

• 45 degrees oblique position

• Chin elevated and protruded

Anatomic landmarks and relation to IR for AP axial oblique

• Msp at 45 degree angle with IR

• C3 centered to IR

CR orientation and entrance point for AP axial oblique

CR angled 15-20 degrees cephalad entering C4

Size of collimated field for PA axial oblique

10×12 inches

Key patient/ positioning points for PA axial oblique

• upright or recumbent

• 45 degrees oblique position anterior oblique position

• Chin elevated and protruded

Anatomic landmarks and relation to IR for PA axial oblique

• Msp at 45 degree angle with IR

• Center C5 to IR

CR orientation and entrance point for PA axial oblique

CR angled 15-20 degrees caudad entering C4

Why should the patient be asked to phonate “ah” softly during the exposure for the AP atlas and axis open mouth?

To place the tongue in the floor of the mouth so that it is not projected on the atlas and axis and prevent movement of the mandible

In the image produced by the AP projection, open mouth technique, which cranial structure should be superimposed with the occlusal surface of the upper central incisors?

Base of the skull

Which areas of cervical vertebrae should be clearly demonstrated with the AP open mouth technique?

Articulations between C1 and C2

What should the patient be instructed to do to prevent superimposition of the mandible and the midcervical vertebrae for the AP axial projection?

Extend the chin enough so that the occlusal plane is perpendicular to the tabletop

How is it determined that the chin has been correctly extended for the AP axial projection?

Occlusal plane is perpendicular to IR

How many degrees and in what direction should the central ray be directed for the AP axial projection?

15-20 degrees cephalad

The AP axial projection for cervical vertebrae should demonstrate the vertebrae from ______ to ______.

C3; T2

From the following list, identify the two evaluation criteria indicating that the patient was properly positioned without rotation for the AP axial projection

• the spinous processes should be equidistant to the pedicles and aligned with the midline of cervical bodies

• The mandibular angles and mastoid processes should be equidistant to the vertebrae

Which of the cervical vertebrae should be demonstrated with lateral projections?

All seven cervical vertebrae

What positioning maneuver is used to prevent the mandible from superimposing the vertebrae for the lateral projection?

Elevate the chin slightly or have the patient protrude the mandible

What breathing instructions should be given to the patient for the lateral projection?

Suspend respiration at the end of full expiration to obtain maximum depression of the shoulders

What should the radiographer do to help overcome the effects of a large object to image receptor distance (OID) created with the lateral projection?

Use a 60-72 inch SID

What should the radiographer do if the C7 vertebra is not well visualized on a lateral projection?

Depress the shoulders

AP axial oblique projections are used for the best demonstration of the pedicles and:

Intervertebral foramina

Why should the patient be instructed to lift and extend the chin for the AP axial oblique projection?

So that the mandible does not overlap the spine

Explain how the positioning of the cervical vertebrae is affected if the patient turns the head until the midsagittal plane of the skull is parallel with the plane of the IR for the AP axial oblique projection

It causes slight rotation of the superior vertebrae

How many degrees and in what direction should the central ray be directed for the AP axial oblique projection?

15 to 20 degrees cephalad

Why is the central ray directed 15 to 20 degrees cephalad for tree AP axial oblique projection?

So that the central ray coincides with the orientation of the foramina

If an AP axial oblique projection is performed with the patient in a recumbent posterior oblique position, should the direction and angulation of the central ray be different from that recommended for an upright patient?

No

Why should a support be placed under the patients head for the AP axial oblique projection with the patient in a recumbent posterior oblique body position?

So that the cervical column is horizontal and parallel with the IR

What breathing instructions should be given to the patient for the AP axial oblique projection?

Suspend respiration

Which of the following procedures should be avoided when positioning for an AP axial oblique projection?

Turning the chin to the side

From the following list, identify the five evaluation criteria indicating that the patient was properly positioned for an AP axial oblique projection?

• the occipital bone should not overlap C1

• The chin should be elevated and not overlap C1 and C2

• All seven cervical vertebrae and T1 should be included

• The intervertebral disk spaces should be open and well demonstrated

• The intervertebral foramina should be open, with foramina farthest from the IR well demonstrated

In what body position is the patient?

RPO

The intervertebral foramina of which side (left or right) are best demonstrated?

Left

Is the anatomy demonstrated closer or or farther from the IR?

Farther

With the patient positioned in the right anterior oblique position, the intervertebral foramina best demonstrated are those on the patients ______ (right or left) side for the PA axial oblique projection

Right

When the patient is in the standing position, to what level of the patient should the IR be centered for the PA axial oblique projection?

C5

How many degrees should the entire body of the patient be rotated?

45

How many degrees and in what direction should the central ray be angled for the PA axial oblique projection?

15 to 20 degrees caudal

Through which cervical vertebrae should the central ray be directed for the PA axial oblique projection?

C4

What position is shown in the image?

LPO

The intervertebral foramina of which side (left or right) are best demonstrated?

Left

Are the open intervertebral foramina demonstrated in this image closer or farther from the IR?

Closer