Flashcards in Lateral/Longitudinal Deck (23):
Why is the projection name longitudinal?
b/c the central ray is directed along the longitudinal axis of atlas.
What is the primary purpose of this film?
Obtain second letter of listing (AS/AI)
What is the secondary purpose of this film?
Evaluate C1/C2 relationship, anomalies, look at cervical curve.
What four things should you check for before analyzing lateral film?
1. Flex/ext. malpostion
2. Rotational malposition
3. Check typical lordotic curve
4. Visual impression of AS/AI
How do you check for flexion/extension malposition?
Comparing hard palate to the top of the film. They should be parallel.
How do you evaluate rotation malposition?
Posterior lines of mandible should be superimposed on each other.
A military or kyphotic neck may tend to show and __ listing?
What are the three lines of the lateral film?
OCL - occipital condyle line
APL - atlas plane line
LL - Listing line
Where do you place dots for occipital condyle line?
Anterior and posterior aspect of occipital condyle and level of floor of skull.
Where do you place dots for APL/atlas plane line?
Base of anterior tubercle and narrowest portion of anterior arch.
How do you make the listing line?
Place parallel on OCL and scroll down to posterior arch dot and draw line.
Where do you measure angle for listing?
Measure angle between the APL and LL
What is the normal degree for the atlas plane line?
4 degrees above the LL
How do we describe a normal listing?
AS listing would be what?
Any measurement above the normal 4 degrees.
AI listing would be what?
Any measurement below the normal 4 degrees
If the APL is ABOVE the LL by more than 4 degrees what do you do?
Subtract 4 from measured angle
If the APL is BELOW the LL what do you do?
Add the 4 degrees to the measured angle.
If the APL line is above the LL be LESS than 4 degrees what listing is it? How do you measure it?
Subtract measured angle from 4.
The patient is place ________ to tube for this film.
The central ray of this film is directed through what?
The transverse process
What is the film distance for lateral x-ray?