Positioning Notes: T-spine & Scoliosis

T-spine Routine Views

AP & Lateral

AP T-spine technique

90 kVp, 8 mAs

AP T-spine

• 40” SID

• 7×17 LW Collimation

• Center @ T7 (3-4” inferior to jugular notch)

• Suspended expiration

• Need entire T spine

AP T-spine breathing

suspended expiration

AP T-spine evaluation criteria

1. all 12 vertebrae

2. wide latitude of exposure

3. x-ray beam should be collimated inside breast shadows

4. spinous processes should appear at midline

5. vertebral column should be aligned to middle of radiograph

Lateral T-Spine/ cross table technique: Manual

90 kVp, 32 mA, 1600ms

Lateral T-spine

• 40” SID

• 7×17 LW collimation

• Center @ T7 (3” below sternal angle, 7-8” below vertebral prominence)

• L marker placed on ANTERIOR side

• need entire T-spine (T1-T3 not as clearly seen due to shoulders causing underexposure)

Lateral T-spine breathing

• Slow, quiet breathing

Why use a low mA & long exposure time (2-3sec) for the lateral T-spine?

to help blur out the rib shadows & lung markings

If breathing technique for lateral T-spine is not available, what do you do instead?

suspended expiration

Lateral T-spine evaluation criteria

1. vertebra shown clearly through rib & lung shadows

2. 12 thoracic vertebrae centered

3. ribs superimposed posteriorly to indicate that there no rotation

4. open intervertebral disk spaces

5. wide latitude of exposure

6. tight collimation to reduce scatter

Merrill’s SID recommendation for Lateral T-spine

48” (to reduce magnification)

Merrill’s recommendation for lateral T-spine

if the long axis of the vertebral column is not horizontal elevate the lower or upper thoracic region with a radiolucent support. this is the preferred method. if not using a support, tube can be angled an avg of 10 degree cephalad for females and 15 degree for males

T-Spine Special View: Cross Table Lateral:

• 40” SID

• 7×17 LW collimation

• center @T7

• left marker, annotate cross table

• same breathing as regular lateral t-spine

• same criteria

Scoliosis: Lateral

recommended with the patient erect to show spondylolisthesis or demonstrate exaggerated degrees of kyphosis or lordosis

Scoliosis: Ferguson method

AP/ PA- the foot on the convex side of the scoliosis curve is raised 3-4 inches (place a block under the foot to keep it elevated). This evaluates and identifies the primary curves from the compensatory curves.

Scoliosis: L/R bending views

Can be done AP/PA erect or AP recumbent. Patient bends laterally as far as possible while using the pelvis as a fulcrum. One is done to the right and one to the left.

scoliosis overview:

• purple 180cm grid- stitching grid

• 102” SID

• shoes need to be off

• MSP centered

• start with 17 x 31 1/2” collimation

  • collimate just below ASIS (v-space) & right below the chin

• L marker 1/2” down

• arm stand out of wall

• deep breath & hold it

why is PA preferred over AP scoliosis?

90% dose reduction to thyroid & breast

scoliosis evaluation criteria:

•  T & L vertebrae to include femoral heads of both hips & acetabulum

• Both iliac crests ENTIRELY 

• Vertebral column aligned down center

scoliosis series means

PA only