SI Joints, Sacrum and Coccyx, Scoliosis Flashcards
(33 cards)
1
Q
AP Axial SI Joint
A
- Pt. supine with legs extended - check for rotation
- CR: 30 for males, 35 for females
- CP: 2” superior greater trochanters at MSP OR 2” inferior ASIS
- suspend respiration
2
Q
AP Axial SI Joint Evaluation Criteria
A
- no rotation
- Both SI joints demonstrated without superimposition from the superior pubic ramus
- open lumbosacral joint (L5/S1)
3
Q
PA Axial SI Joints
A
- Pt. prone - check for rotation
- CR: 30 caudad for males
- CR: 35 for females
- CP: PSIS at MSP
- suspend respiration
4
Q
If pubic symphysis is superimposed with the SI joints what does that mean in regards to the angle that was used?
A
there is too much angle
5
Q
AP Oblique SI Joints
A
- rotate patient 25-30 from supine
- use sponges - keep entire body straight
- side furthest from IR is demonstrated - the raised side
- CR: perpendicular
- CP : 1” medial to raised side ASIS - at the level of the ASIS
- suspend respiration
6
Q
AP Oblique SI Joint Evaluation Criteria
A
- open SI joint
- AP - center on the raised side
- minimal overlapping of the ilium and sacrum
7
Q
AP Axial Sacrum
A
- Pt. prep - empty bladder - ordering physician may request a cleansing enema
- hospital pants
- pt. supine legs extended
- CR: 15 cephalad
- CP: 2” superior to pubic symphysis or 2” below ASIS at MSP
8
Q
AP Axial Sacrum Evaluation Criteria
A
- No rotation
- Entire Sacrum with no foreshortening
- Pubic bones not overlapping sacrum
- tight collimation
- open sacral foramina
9
Q
AP Coccyx
A
- Pt. supine - legs extended
- CR: 10 caudad
- CP: 2” superior pubic symphysis at MSP
10
Q
What image is a good example of a bisecting angle technique?
A
AP Axial Sacrum
11
Q
AP Coccyx Evaluation criteria
A
- entire coccyx demonstrated with segments not superimposed
- no rotation
- tight collimation
- no superimposition with pubic bones; coccyx must be superior (and should be in line with pubic symphysis)
12
Q
Lateral Sacrum/coccyx
A
- Pt. on left side with knees flexed
- CP: 3.5-4” posterior to the ASIS (textbook answer)
- CP: dependant on knee flexion and pelvic tilt - midway between crest and trochanters
- Align CR so it passes through both PSIS (small caudad angle)
- lead masking on table
- always include coccyx
13
Q
Lateral Sacrum/coccyx evaluation criteria
A
- sacrum and coccyx should both be seen clearly
- tight collimation
- superimposed acetabula and greater sciatic notches
14
Q
Lateral coccyx
A
- pt. on left side
- CR: perpendicular
- CP: 3.5-4” posterior to ASIS and 2” superior level of greater trochanter
- light below level of greater trochanter
- sponge under the lower back/ asses for angle with PSIS
- lead masking on table
15
Q
Lateral coccyx evaluation criteria
A
lateral coccyx visualized completely, including distal end of sacrum
16
Q
What is scoliosis?
A
idiopathic, functional, neuromuscular and degenerative
17
Q
When does scoliosis appear?
A
idiopathic typically appears during adolescence
18
Q
What must we consider when imaging scoliosis?
A
- How much deformity does the patient have - determines hoe much we collimate
- Can the patient stand
- How old is the patient - most are adolescents - rad protection - high kVp and low mAs - image PA
- image quality - see entire spine on 1 image
19
Q
CR Stitching for Scoliosis
A
- 2-3 CR cassettes can be attached together to achieve desired length
- uses computer software called image stitching to produce one image from all the cassettes
- follow procedures and protocols of specific vendor
20
Q
Scoliosis classifications
A
non-structural (secondary or compensatory)
structural
21
Q
what is non-structural scoliosis?
A
- temporary curvature
- muscle spasm, leg length discrepancy, hip dysplasia, poor posture or just to compensate for structural curve
- curve disappears when supine, with side bending or the cause is removed
22
Q
what is structural scoliosis?
A
- curvature is permanent (unless treatment is offered)
- curve does not disappear when supine or with side bending
- sometimes referred to as the “primary” curve
23
Q
structural scoliosis imaging considerations
A
- primary or structural curves need to be repaired if large enough
- body produces a compensatory curve (Secondary, non-structural) to keep the body aligned
- compensatory curve will be in the opposite direction from the primary or structural curve
- when supine, eliminating gravity eliminates the compensatory curve
- rotation in addition to lateral curvature - vertebral body rotates towards convex side of the curve
24
Q
What views are acquired. in a scoliosis series?
A
- AP/PA upright
- AP/PA supine/prone
- AP/PA with lateral bending
- Lateral Upright
25
Why do we perform an AP/PA upright?
to assess the degree of curvature (Cobb angle) with the force of gravity
26
Why do we perform an AP/PA supine/prone?
to assess structural from non-structural curves
27
Why do we perform an AP/PA with lateral bending?
to assess primary from secondary curves and mobility
28
Why do we perform a lateral upright?
to assess the degree of kyphosis or lordosis - degree of anterior or posterior curvature
29
PA or AP upright
- allow patient's arms to hang relaxed
- do not support patient
- do not use a compression band
- include from base of skull to ASIS/PSIS
- minimum SID of 150 cm
- CP depends on CR vs DR
30
Degree of Curvature
Cobb Angle
- determine the vertebra whose endplates are most tilted towards each other
- lines are drawn along the top of the superior tilted vertebra and the bottom of the inferior tilted vertebra
- two more lines are drawn at an angle of 90 of these lines, so that they intersect
- the resulting angle = Cobb angle
31
Cobb angle indications
- less than 20 normal
- 20 - 40 = brace (can stop progression if caught early on)
- > 40 - 50 = rods, spinal fusion
32
Lateral upright
- do not use compression band
- support arms - straight ahead
- EAM to ASIS
- SID min of 150cm
- CR: perpendicular
- CP: depends on CR vs DR
- Assesses degree of kyphosis and lordosis
33
Side bending images
- to assess structural from non-structural curves
