C-Spine Positioning Flashcards
Lordotic curves - convex anteriorly
C spine, L spine
Kyphotic curves - concave anteriorly
T spine, sacral
Articular processes, superior and inferior articulate
Zygapophyseal, interarticular facet joints
What are the 3 unique characteristics of a typical cervical vertebrae?
- Bifid spinous process
- Articular pillar
- Three foramina
How are zygapophyseal joints best demonstrated?
True lateral position
How are intervertebral foramen best demonstrated?
45 degree oblique
15 degree cephalic (PA), caudad (AP)
The superior and inferior articular processes of cervical vertebrae have fused on either or both sides
Columns of bone that project laterally from the junction of the lamina and pedicle
Articular pillars
Hook shaped process, or bony perturbance located on lateral or posterolateral margins of superior endplates of C vertebrae
Most common C3-7
Uncinate processes
Vertebra prominens
C7
What kv is used for C spine projections?
75-85
What kv is used for lateral swimmers?
80-95
What projections use an SID of 100 cm?
AP, open mouth, swimmers
What projections use a SID of 150-180cm?
Lateral, obliques (increased OID)
What AEC cell is used for all projections except AP open mouth?
Center
AP open mouth, none
What are the essential projections for C spine?
-AP axial
-AP open mouth
-Lateral
-Oblique
PA (RAO, LAO)
AP (RPO, LPO)
1 inch distal to EAM
C1
-best demonstrates zyga joints
-MCP perpendicular to IR
-center C4
-shoulders relaxed, chin elevated, mandible protruded
Lateral C spine
This projection is needed when C7 and top of T1 is not well demonstrated on lateral C spine
Lateral cervicothoracic (swimmers)
What should the collimated field for lat. C spine include?
Include 1 inch above EAM to top of T1 body
*if top 1/3 of T1 is not demonstrated, lateral of cervicothoracic is required
-true lateral
-separate shoulders (lift arm)
-CR to T1, 1 inch above jugular notch
-shoulder further from IR depressed
-C7-T1 interspace centered
Lateral cervicothoracic (swimmers)
If the shoulder can not be depressed for a lateral cervicothoracic (swimmers), what angulation can be used?
3-5 degree caudad
-intervertebral foramina on side closer to IR is demonstrated
-15 degree caudad
PA oblique (LAO, RAO)
*down, down, down
-intervertebral foramina on side farther from IR is demonstrated
-15 degree cephalic
AP oblique (LPO, RPO)
*up, up, up
T/F
In an xray image, there is no way to tell if the oblique C spine was done AP OR PA
True
Why are both obliques taken?
To compare sides
What position is the patient in for a PA oblique projection?
Anterior oblique position
-head and body at 45 degree angle to IR
-c spine in center of IR
-IR at level C4
-chin elevated and protruded
Oblique
T/F
The head can be rotated at 45 or 90 degrees for an oblique projection
True
-MCP parallel to IR
-C4 centered
-MSP of head perpendicular
-extend chin and place occlusal plane perpendicular to tabletop
AP axial c spine
What angulation is used for an AP axial?
15-20 degrees cephalic
-15 for supine
-20 for upright
Why is a larger angle (20) used for upright compared to supine AP axial?
More lordosis when upright
What does the collimated files present for an AP axial c spine?
C3-T2 and surrounding soft tissue
-align edge of upper incisors and base of skull (mastoid tips) perpendicular to IR
-mouth open as wide as possible
-CR enters at midpoint of open mouth
AP C1-2 open mouth
*collimated field includes upper incisors to tip of chin
C1-2 in center of field
T/F
The upper incisors and base of skull should be superimposed for open mouth projection
True
