c spine positioning quiz: AP fuchs, lateral flexion/extension, swimmers

Size of collimated field for AP Dens (Fuchs)

5×5 inches

Key patient/ positioning points for AP Dens (Fuchs)

• supine

• MSP of head perpendicular to IR

• Chin extended and place top vertical

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

• Mastoid tip and tip of chin aligned

• Perpendicular to IR

CR orientation and entrance point for AP Dens (Fuchs)

CR perpendicular to MSP just distal to the tip of chin

Evaluation criteria for AP Dens (Fuchs)

• entire dens within the foramen magnum

• No rotation of the head or neck, demonstrated by symmetry of the mandible, cranium, and vertebrae

True or false:

The AP projection (Fuchs method) should be used to demonstrate an upper cervical fracture in trauma patients

False

True or false:

In the image of the AP projection (Fuchs method), the entire dens should be seen within the foramen magnum

True

What two structures are aligned for the AP projection (Fuchs method) of the dens?

The chin and tips of the mastoid process

Size of collimated field for Lateral hyperflexion/hyperextension

• 10×12

Key patient/ part positioning points for lateral hyperflexion

• upright lateral

• MSP parallel to IR

• Drop chin to chest

Key patient/ part positioning points for lateral hyperextension

• upright lateral

• MSP parallel to IR

• Elevate chin as much as possible

Anatomic landmarks and relation to IR for lateral hyperflexion/ hyperextension

IR centered to C4

CR orientation and entrance point for lateral hyperflexion/ hyperextension

CR perpendicular to C4

Evaluation criteria for lateral hyperflexion

• all seven cervical vertebrae in true lateral position

• No rotation or tilt of the cervical spine

• Superimposed zygapophyseal joints and open intervertebral disk spaces

• Superimposed or nearly superimposed rami of the mandible

• Spinous processes shown in profile

• Body of the mandible almost vertical in a normal plane

• All seven spinous processes in profile, elevated and widely separated

Evaluation criteria for lateral hyperextension

• all seven cervical vertebrae in true lateral position

• No rotation or tilt of the cervical spine

• Superimposed zygapophyseal joints and open intervertebral disk spaces

• Superimposed or nearly superimposed rami of the mandible

• Spinous processes shown in profile

• Body of the mandible almost horizontal in a normal plane

• All seven spinous processes in profile, depressed and closely spaced

Describe how the patients head and neck should be adjusted from the neutral lateral position for the hyperflexion position

Drop the head forward

Describe how the patients head and neck should be adjusted from the neutral lateral position for the hyperextension position

Elevate the chin as much as possible

In an image with the patient in the hyperflexion position, how is it determined that the patients neck has been flexed far enough?

The body of the mandible should be vertical

In an image with the patient in the hyperextension position, how is it determined that the patients neck has been extended far enough?

The body of the mandible should be horizontal

What cervical vertebrae should be clearly demonstrated in images produced with the patient in the hyperflexion and hyperextension positions?

All seven cervical vertebrae

Indicate how the cervical spinous processes should appear in images with the patient in the hyperflexion lateral position

Elevated and widely separated

Indicate how the cervical spinous processes should appear in images with the patient in the Hyperextension lateral position

Depressed and closely spaced

The swimmer’s technique is performed when ____________________________

shoulder imposition obscures C7 on a lateral c-spine projection or when a lateral projection of the thoracic vertebra is needed

Which body plane should be centered to the midline of the grid for the swimmers technique?

Midcoronal plane

With reference to the patient, where should the IR be centered for the swimmers technique?

At the level of the C7-T1 intervertebral disk space

Describe how the patients arm should be positioned for the swimmers technique

• extend the arm closest to the IR above the head. If the patient is upright, flex the elbow and rest the forearm on the patients head

• Position the arm away from the IR down along the patients side and depress the shoulder as much as possible

Describe how the patients shoulders should be positioned for the swimmers technique

• elevated arm is rotated anterior

• Depressed arm rotated posterior

List the two ways that the patients respiration can be controlled for the swimmers technique

• suspend

• A breathing technique can be used to blur the lung anatomy if the patient can cooperate and can be immobilized

Which two ways can the central ray be directed for the swimmers technique?

Perpendicular or 3 to 5 degrees caudad

For the swimmer’s technique, the patient may be positioned either _____________

• Recumbent or upright

• Right or left lateral

When the patient is positioned recumbent, where should the body be supported to maintain the long axis of the cervicothoracic vertebrae in a horizontal position for the swimmers technique?

Under the lower thorax

With reference to the patient, to what specific location should the central ray be directed for the swimmers technique?

• disk space of C7 and T1

According to Mondas recommendation, how many degrees and in which direction should the central ray be directed?

5 to 15 degrees cephalad

Identify the four evaluation criteria indicating that the patient was properly positioned for a lateral projection of the cervicothoracic region

• the exposure must have penetrated the shoulder area

• The shoulders should be seen separated from each other

• The area from approximately C5-T4 should be included

• The vertebrae should be lateral and not appreciably rotated