CXR Technical Adequacy

Question 1

List some uses for CXRs

Answer 1

Respiratory disease
Cardiac disease
Metastases
Trauma
Pre-operative imaging
Pre-employment physicals
Medical fitness
Immigration screening
Excluding foreign bodies (aspiration, MRI safety screen)
Checking position of NG tubs, ET tubes, PICCs, etc.

Question 2

What do PA and AP mean?

Answer 2

Posteroanterior vs anteroposterior

Question 3

________ view is standard for CXR bc the heart is closer to film

Answer 3

PA

Question 4

Structures that the beam hits first appear _________

Answer 4

larger

Question 5

Structures that are closer to film appear ________

Answer 5

clearer

Question 6

What are the 5 technical factors to determine if CXR is adequate for interpretation?

Answer 6

Penetration
Inspiration
Rotation
Magnification
Angulation

Question 7

Why is penetration important?

Answer 7

X-rays must adequately pass through the body to visualize necessary structures

Question 8

How do you know if you have adequate penetration on a CXR?

Answer 8

You should be able to see the thoracic spine through the heart shadow

Question 9

Define under-penetration

Answer 9

Cannot see thoracic spine through the heart

Question 10

Under penetration:
1) What is not visible? Why is this a bad thing?
2) What is more prominent? Why is this bad?

Answer 10

1) Left hemidiaphragm not visible; cannot differentiate left lower lung disease
2) Pulmonary markings more prominent; may mistake for CHF or pulmonary fibrosis

Question 11

Over penetration:
1) What is decreased/ absent? Why is this bad?
2) What is obscured?

Answer 11

1) Lung markings decreased/absent; might mistake for emphysema or pneumothorax
2) Pulmonary nodules obscured

Question 12

Inspiration:
What is standard? What are two reasons for this?

Answer 12

Full inspiration is standard:
1) Ensures reproducible images for comparison
2) Eliminates artifacts

Question 13

Inspiration:
1) At least ___ posterior ribs should be visible
2) ____ ribs = excellent inspiration

Answer 13

1) 8
2) 10

Question 14

Inspiration:
1) ____________ ribs are more apparent
2) Describe these ribs

Answer 14

1) Posterior
2) Oriented horizontally + attached to thoracic vertebrae

Question 15

Inspiration: Describe the anterior ribs

Answer 15

1) Less visible
2) Oriented downward
3) Cartilaginous sternal attachments not visible

Question 16

Which ribs do you count on CXR? Which side?

Answer 16

Posterior; count on the right in most cases

Question 17

1) Describe the first rib
2) What freq. overlaps the first rib?

Answer 17

1) Shaped like a C
Much smaller
Intersects clavicle
2) 2nd frequently overlaps the 1st

Question 18

Rotation:
1) Why is [lack of] rotation important?
2) How do you tell if rotation is appropriate (i.e. no rotation)?

Answer 18

1) Identify clavicles and thoracic spine
2) Distance between t-spine and ends of clavicle should be similar

Question 19

Rotation can alter contours of structures, such as?

Answer 19

Heart
Great vessels
Hemidiaphragm

Question 20

Magnification:
1) ____________ is important in assessing size of heart
2) Farther from film = appears _________ ( ex/ AP view)
3) ______ position solves this issue for the most part

Answer 20

1) Positioning
2) larger
3) PA

Question 21

Angulation:
X-ray beam should pass _________ to floor; thorax should be ____________

Answer 21

parallel; perpendicular

Question 22

Angulation:
Explain the apical lordotic effect

Answer 22

Beam is angled upward on upright patient or
Beam is horizontal on semi-recumbent patient
Anterior structures projected higher

Question 23

Angulation:
1) Angulation distorts what?
2) Obscures what?
3) How do you check for angulation?

Answer 23

1) heart shape
2) left hemidiaphragm
3) Clavicles at or above first rib