Spinography Flashcards
12 signs of posteriority on the lateral x-ray:
- visual posteriority
- anterior coccyx
- posterior S2 tubercle
- BP sacrum
- spondylo
- stair-stepping
- stacking
- Schmorls node
- eburnation
- exostosis
- disc degeneration
- hour glassing
What is true about X-ray distortion?
distortion can alter the degree in which the vertebrae appear to be misaligned but does NOT alter the direction
How does C1/C0 misalignment affect the spinal canal?
AS–>canal smaller
PS–>canal is larger
For every 5mm of ___ misalignment, the femur head will be 2mm lower
PI or EX
For every 5mm of ____the femur head will be 2mm higher
AS or IN
For every 5mm of ____ correction, the femur head will be raised 2mm
PI or EX
For every 5mm of ____correction, the femur head will be lowered 2mm
AS or IN
What is the most important change the AS ilium undergoes, when analyzing the x-ray?
decrease innominate measurement compared to the PI side
How does the distance between PSISs change in relation to IN/EX ilium?
- IN–> closer to center of sacrum
- EX–>further to center of sacrum
When is the optimal relationship between 2 vertebrae found?
- when the perimeters of the bodies are in line
- the vertical distance between opposing surfaces of the bodies are the same at ALL points (parallel discs) allowing for nucleus to act as a pivotal ball bearing joint
Why do vertebra in C spine appear non-parallel
- posterior lipping of subjacent vertebra
- lateral uncinate processes
When the axis/atlas plane lines are not parallel, what can you infer?
- atlas has gone anterior–>lateral film
- side of laterality–>A-P film
How much rotation of the sacrum needs to be present in order to list it?
Greater or equal to 7mm
How do you determine a base posterior sacrum?
look at lateral x-ray
Compare the Sacrum to L5–>sacrum will be posterior to L5
L5 disc wedge open to posterior
How do we measure the degree of an ilium misalignment on the AP x-ray?
we measure the differences in mm and write them as subscripts
2 contradictions to x-ray:
- pregnancy
- radiation exposure
Normal sacral angle:
35-40 degrees
What are 20 indiations to X-ray?
- Pathology
- Anomaly
- Fracture
- Dislocation
- Malformation
- Accurate count
- Segmental relationship
- Spinal contour
- Exact relation of adjacent segments
- Specific listings
- Disc condition
- Disc spatial relationship to level
- Surrounding tissue
- Motion studies for biomechanics of disc under stress
- Prosthesis
- Posture analysis
- Progress change
- Patient education
- Court cases
- Because every spine is different
3 ways to determine atlas rotation?
- measuring lateral masses
- measuring radiolucency on medial borders of lateral masses
- atlas/occiput condyle lines will converge on side of anterior rotation
4 reasons why we use/prefer full-spine films:
- Less radiation than sectionals
- Provide accurate vertebral count
- Provide full spinal contour for posture analysis w/axial weight-bearing
- Shows problems other than chief complaint
14 reasons to take a full spine x-ray over a sectional x-ray
- 2 films
- 3 exposures
- less radiation
- less film cost
- time
- full spine contour
- exact relation of adjacent segments
- posture analysis
- accurate count of segments
- good for patients that can’t stand long
- much easier to read
- much easier to analyze
- less chance for mistakes
- better for patient education
3 ways to list body rotation in order of reliability:
- width of articular process–> lesser width on side of spinous rotation:: L5 especially
- Pedicle Shadows:: rest of spine
- Spinous rotation:: least reliable
How do you determine vertebral wedging on AP x-ray?
- vertebral endplates
- superior junction of TVP and body
- superior/inferior pedicle borders
Which term describes the actual difference in length of the patient’s leg?
Actual or anatomical deficiency
Which term describes the difference in height of the 2 femur heads as they appear on A-P film?
Measured deficiency
What measurement is used to determine leg length PRE-adjustment?
Measured deficiency
What measurement is used to determine leg length POSTadjustment
Actual/Anatomical deficiency
What is the allowable yearly dose for radiation workers?
5 rem
How much radiation does one get from full spine x-rays (A-P & lat.)?
2mrem
3 considerations when the ilia are not equal on the x-ray?
- pathological or congenital condition
- poor positioning on the x-ray
- misalignment of the pelvis
Tube distance of full spine x-rays:
- Lateral 72’’ FFD
- AP 84’’ FFD
Film size of full spine x-rays:
- Lateral- 2 exposures 14’’ X 18” film each
- AP - 1 exposure, 14’’ X 36” film
How many mm of deficiency is the body able to adapt to?
- <6mm
- >6mm causes subluxations
How often will a thoracic vertebra show inferiority on film?
- Rarely
- because of the ribs and their ligament that bind to the thoracic spine
When occiput is subluxated, what do you expect to find with the atlas and axis on A-P film?
- Atlas and axis will be parallel
- Because the principal motion is rotation around the odontoid (not laterally)
When C0/C1 are aligned, what is the angle formed on the lateral x-ray between the lines?
~5 degrees
AS occiput decreases angle
PS occiput increases angle
Should you take a different x-ray if visualization changes on the patient?
YES, because now it’s a new patient
How do you measure for sacral inferiority?
- roll your parallel to the highest sacral point from the femur head line
- Strike a line
- if this coincides with posteriorly rotated side, then you have sacral inferiority
