L Spine Technique Flashcards
how is the pt positioned for an AP l spine? - 6 points
pt supine with head resting on pillow, arms relaxed at pt’s sides, long axis of pt coincident with midline of the table, ASISs equidistant to table top ensuring no rotation, MSP at 90 degrees to table top, ensure alignment of pt to image receptor
how is the tube positioned for an AP l spine?
where is the tube centred to?
what is the breathing?
what is the SID?
direct vertical central ray at 90 degrees to pt
lower costal margin in the midline
on arrested respiration
100cm
what can be done to reduce the secondary curvature of the l spine and how does this work?
what is a further advantage of this?
flex the knees bringing the posterior aspect of the pt in contact with the table top
visualisation of the intervertebral joint spaces is enhance because the joints are aligned with the central ray
what should be collimated into the AP l spine image?
t12 superiorly
proximal 2/3 of sacrum and whole SIJs inferiorly
soft tissues lateral to l spine (to exclude renal pathology)
what should be seen on the AP l spine image? - 4 points
vertebral bodies coincident with midline
spinous processes central to vertebral bodies
intervertebral space in joints
equal proportion of transverse process projected lateral either side of vertebral bodies
what would be seen on an ideal AP l spine image? - 7 points
corticol outlines of the vertebrae should be intact and trabecular pattern comparable between each vertebrae
size of vertebral bodies increases progressively from l1-l5
interspinous distance should be approx equal throughout the l spine so no widening/loss of joint space
spinous processes should be centralised throughout the l spine so no disruption of the vertebral alignment
inter-pedicular distance should be virtually equal throughout the l spine so no disruption of the vertebral bodies
pedicles and transverse processes should be symmetrical throughout l spine so no disruption of the vertebral alignment
no evidence of abnormal soft tissue outlines, which would indicate para-vertebral swelling
what can be used to improve image quality and how does this work?
a lead rubber sheet can be used in order to see the posterior vertebral border more clearly as scatter will have been absorbed
how is it decided which lateral is carried out on pt’s who have scoliosis and why?
you centre to the side that has the concavity of the curve with the pt lying on the side that has the convexity of the curve
this is due to the attenuating beam as it passes through the pt being better lined up to pass through the joint spaces if centred to the concavity of the curve
what is collimated into a lateral l spine image?
t12 superiorly
proximal 2/3 of sacrum inferiorly
soft tissues anterior and posterior following the curvature of the spine
what should be included on a lateral l spine image? - 4 points
vertebral bodies coincident with the midline of the image receptor
superimposition of anterior, posterior, superior and inferior borders of the lateral bodies
evidence of intervertebral space
intervertebral foramina superimposed
how is the pt positioned for a L5/S1 junction? - 5 points
pt rolled onto affected side with posterior aspect facing rad, elbows flexed and pt’s arms anterior, pt’s shoulders and hips adjusted so in same plane allowing MSP to be parallel to table top, long axis of spine coincident with midline of image receptor, knees and ankles flexed for stability
how is the tube positioned for a L5/S1 junction?
where is the tube centred?
what is the SID?
what is the breathing?
direct vertical central ray at 90 degrees
5cm anterior to spinous process of L5
100cm
on arrested respiration
what would be seen on an ideal L5/S1 junction image? - 6 points
vertebral corticol outlines should be intact and trabecular pattern comparable throughout L4/L5 and sacrum
size of sacrum decreases progressively from S1-S5
no widening or loss of joint space L4/L5 and L5/S1
spinous processes of L4/L5 should be aligned and not foreshortened
symmetry and alignment of intervertebral foramina L4/L5 and L5/S1
no evidence of abnormal soft tissue outlines which would indicate para-vertebral swelling
how is the pt positioned for a lateral sacrum? - 4 points
pt rolled onto affected side, elbows flexed and pt’s arms resting anteriorly, pt’s shoulders and hips adjusted so in same plane allowing MSP to be parallel with midline of receptor, knees and ankles flexed for stability
how is the tube positioned for a lateral sacrum?
where is the tube centred?
what is the SID?
what is the breathing?
direct vertical central ray at 90 degrees
point midway between the PSIS and the sacro-coccygeal junction
100cm
on arrested respiration
