thoracic spine technique

Question 1

clinical indications for t-spine (10 indications)

Answer 1

1) compression #
2) wedge #
3) chance #
4) dislocation
5) scoliosis
6) kyphosis
7) spondylosis
8) ankylosing spondylitis
9) osteoporosis
10) metastatic disease

Question 2

6 ways radiation protection for t-spine

Answer 2

1) identification check
2) careful technique to avoid repeats
3) gonad protection applied wherever practicable
4) efficient collimation
5) application of the 28 day rule
6) consider using alternative imaging modalities e.g. ultrasound

Question 3

how does the patient lie on the table

Answer 3

supine with the head resting on the pillow and arms relaxed at the patients side

Question 4

what is the long axis of the patient in relation to the midline of the table (AP position)

Answer 4

long axis is co-incident with the midline of the patient

Question 5

what should the ASIS’s be to the table top (AP)

Answer 5

equidistant in order to prevent rotation

Question 6

what is MSP

Answer 6

median sagittal plane

Question 7

what is the MSP of the patient to the table top (AP)

Answer 7

MSP is 90 degrees to table top indicating no rotation

Question 8

how should the patients head be (AP) and why

Answer 8

the head should be raised to ensure the chin is clear of the upper thoracic area

Question 9

where and what ray should be used for an AP t-spine

Answer 9

should direct the vertical ray 90 degrees midway between the sternal notch (T1) and the xiphi-sternum (T12) in the midline

Question 10

what anatomical point is associated with T1

Answer 10

the sternal notch

Question 11

what anatomical point is associated with T12

Answer 11

the xiphi-sternum

Question 12

what should be ensured of the patient to the imaging receptor

Answer 12

alignment

Question 13

how should an AP t-spine be done; on what breathing and SID

Answer 13

expose on arrested respiration using an SID of 100cm

Question 14

what is the correct area of interest for an AP t-spine (3 points)

Answer 14

1) C7 superiorly
2) Just below L1 inferiorly
3) Costo-vertebral joints and medial 1/3 of ribs, laterally

Question 15

what is the correct positioning for an AP t-spine (5 points)

Answer 15

1) vertebral bodies to be co-incident with midline of imaging receptor
2) spinous processes central to vertebral bodies
3) evidence of intervertebral joint space
4) sternal ends of clavicle equidistant from spine indicating no rotation
5) mandible clear of upper thoracic cavity

Question 16

what are the other 8 image criteria (other than AOI and positioning)

Answer 16

1) correct name
2) correct aspect marker
3) no artefacts
4) evidence of collimation
5) need for repeats
6) further views
7) correct exposure factors
8) evidence of pathology

Question 17

what should the cortical outlines and trabecular patterns be

Answer 17

1) cortical outlines of the vertebrae should be intact

2) trabecular pattern should be comparable between each of the vertebrae

Question 18

what happens to the size of the vertebral bodies

Answer 18

increases progressively from T1 to T12

Question 19

what should the interspinous distance be

Answer 19

approximately equal throughout the throracic spine indicating no widening or loss of joint space

Question 20

what should the spinous process be (AP t-spine)

Answer 20

centralised throughout the t-spine indicating no disruption of the vertebral alignment

Question 21

what should the inter-pedicular distance be

Answer 21

virtually equal throughout the t-spine indicating no disruption of the vertebral bodies

Question 22

pedicles and transverse processes should be

Answer 22

symmetrical throughout the t-spine indicating no disruption of the vertebral alignment

Question 23

there should be no evidence of…

Answer 23

abnormal soft tissue outlines

Question 24

what to abnormal soft tissue outlines indicate

Answer 24

para-vertebral swelling

Question 25

why do we use expiration for a t-spine (2 points)

Answer 25

1) as there is less contrast as the lungs are not fully filled with air
2) expiration is seen as the phase where the body is at rest and organs in the ‘true’ anatomical position

Question 26

how should the patient lie for a lateral t-spine

Answer 26

patient rolls onto affected side (posterior aspect of patient facing radiographer)
elbows flexed and patients arms resting anteriorly

Question 27

how are the patients hips and shoulders adjusted and why

Answer 27

so that they are in the same plane, allowing MSP to be parallel to the table top

Question 28

the long axis of the patient is what with the image receptor (lateral)

Answer 28

co-incident with the midline of the IR

Question 29

how should knees and ankles be and why

Answer 29

flexed to aid stability

Question 30

where and what ray should be used for a lateral t-spine

Answer 30

a direct vertical central ray 90 degrees to 2.5cm behind the mid-axillary line at the level of the inferior angle of the scapula (the postero-inferior aspect of the axilla)

Question 31

what SID is used for lateral t-spine

Answer 31

100cm

Question 32

where is a lead rubber sheet placed and why

Answer 32

posterior to thoracic region to improve image quality by absorbing scattered radiation

Question 33

on what respiration should a lateral t-spine be taken

Answer 33

arrested respiration

Question 34

why is a longer exposure time used for a lateral t-spine

Answer 34

patient breathes throughout the exposure to blur out the overlying ribs and visualise the vertebrae more clearly

Question 35

what is the correct area of interest for a lateral t-spine (4 marks)

Answer 35

1) C7 superiorly
2) L1 inferiorly
3) Soft tissue borders posteriorly
4) Soft tissues anteriorly following the vertebral line

Question 36

Correct positioning for lateral t-spine (4 marks)

Answer 36

1) Vertebral bodies to co-incident with midline of image receptor
2) Superimposition of anterior, posterior, superior and inferior borders of vertebral bodies
3) Evidence of intervertebral joint space
4) Intervertebral foramina open and superimposed

Question 37

what should there be for posterior ribs (lateral)

Answer 37

symmetry and alignment