Positoning Of L Spine

Question 1

Routine lumbar protocol

Answer 1

• AP
• lateral
• lateral L5-S1 (spot)

Question 2

L spine techniques

Answer 2

• AP: 90 Kvp @ 30 mAs

- lateral: 90 kVp @ 60 mAs

Question 3

AP L spine

Answer 3

• 110 SID
• 20 X 35 lightfield
• make sure pt is nice and straight (go to head end of table)
• put sponge under patients knees (45 degree sponge)
• center at 2 fingers above crest (- crosshair)
• make sure equal amounts of light on either side
• bottom of light at ASIS
• top of light you get what you get
• collimate side to side two fingers from ASIS in on both sides
• shield legs
• marker in top of lightfield
• breathe in and all the way out and hold

Question 4

Oblique L spine

Answer 4

• 110 SID
• 20 X 35 lightfield
• make sure pt is lying straight
• 45 degree sponge under patient
• make sure that leg that isn’t touching table is straight and other leg against the table is bent slightly
• make sure pt is running parallel to the table and arms in front (anterior)
• center at 2 fingers above crest
• bottom of light at ASIS
• top of light you get what you get
• (I line middle of clavicle)
• marker on straight leg side at bottom (R marker)
• shield legs
• lengthwise crosshair should aim straight down leg
• breathe in and all the way out and hold

Question 5

Lateral L spine

Answer 5

• 110 SID
• 20 X 35 lightfield
• make sure hips and shoulders are stacked in 90 degrees
• palpate spinous processes
• put sponge to make back straight (put under back almost at hip)
• make sure body is parallel to table
• center two fingers above crest
• middle crosshair (I) centered slightly posterior (close to back of armpit)
• should not have light anterior to ASIS (2 fingers posterior should be start of light)
• bottom of light at bottom of ASIS (palpate PSIS back dimples to make sure straight)
• put lead blocker by sponge
• marker in bottom left of patient (anterior bottom corner)
• breath in, breathe all the way out and hold

Question 6

lateral L5-S1 (spot)

Answer 6

• 110 SID
• 12 X 12 lightfield
• get patient in lateral, with hips and shoulders stacked at 90 degrees
• put sponge to make sure back is straight after palpating spinous processes (put sponge under back before bum)
• put hand at top of crests palm down that is (-) crosshair
• put other hand where that one ends (at ASIS) and palm in and that is your (I) crosshair
• palpate PSIS to make sure straight and make sure hips and shoulders are stacked
• bottom (posterior knight should be at PSIS)
• make sure pt is parallel to table
• center at back of armpit (I)
• marker anterior bottom corner
• lead blocker
• shield legs
• breath in, breathe all the way out and hold

Question 7

Evaluation criteria AP L spine

Answer 7

-T12
-all 5 lumbar vertebral bodies
-SI joints
No rotation shown by:
-sacroiliac joints equidistant to vertebral column
- R and L transverse processes equal in length
-spinous processes centered to spine
-no rotation of pelvis

Question 8

Lumbar obliques are taken to demonstrate?

Answer 8

Zygapophyseal joints

• posterior oblique: downside joints visualized
• anterior oblique: upside joints visualized

Question 9

AP oblique evaluation criteria for L spine

Answer 9

• unilateral zygapophyseal joints from L1 to L5
• pedicles centered in vertebral body
• no tilt

Question 10

For lateral lumbar spine the CR shoots through the

Answer 10

Intervertebral foramina

Question 11

Lateral L spine evaluation criteria

Answer 11

• all lumbar vertebral vertebrae
• T12 thru S1 intervertebral disk spaces
• L1 to L4 intervertebral foramina
• no tilt: open intervertebral disk spaces
• no rotation: posterior edges of vertebral bodies superimposed
• nearly superimposed iliac crests (if no angle on tube)

Question 12

Evaluation criteria for lateral L5/S1 L spine (spot)

Answer 12

• L5/S1 centered in image
• open L4/L5 and L5/S1 joint spaces
• no rotation
• close collimation