EXAM #1: INTRO TO CHEST RADIOLOGY

Question 1

What are the four different densities on a CXR?

Answer 1

1) Soft tissue (water)
2) Fat
3) Air
4) Bone (calcium)

Question 2

How do high density objects appear on CXR?

Answer 2

White

*Note that these are absorbing more photons

Question 3

How do low density objects appear on CXR?

Answer 3

Black

*Note that these are absorbing fewer photons

Question 4

What are the three things to look for to determine of a CXR is adequate for interpretation?

Answer 4

1) Full inspiration
2) Apex of the right hemidiaphragm should be at the level of the posterior 9th or 10th ribs
3) Non-rotated film

Question 5

How much “penetration” should there be on a PA CXR?

Answer 5

T-spine should be just visible, but no detail

Question 6

How much “penetration” should there be on a lateral CXR?

Answer 6

Spine should darken as you move caudally

Question 7

Where do you look for rotation on a CXR?

Answer 7

Clavicles–should be equal distance from the spinous process of the vertebral body

Question 8

How do you tell the difference between a posterior and anterior rib?

Answer 8

Posterior= horizontal
Anterior= vertical

Question 9

What is the significance of the right paratracheal stripe?

Answer 9

Should be less than 5mm

*Enlargement can be lymphadenopathy most commonly associated with lung cancer

Question 10

What forms the right heart border?

Answer 10

Right atrium

Question 11

What is the AP window?

Answer 11

Space between the aorta and the pulmonary artery

Question 12

What do you need to have to visualize structures on a CXR?

Answer 12

Different densities

Question 13

What forms the left heart border?

Answer 13

Left ventricle

Question 14

What is a fissure?

Answer 14

Adjacent viseral pleura

Question 15

What is the difference between the fissures in the right and left lung?

Answer 15

Right= 2x

• Horizontal= superior
• Oblique= inferior

Left= 1x major fissure

Question 16

What fissure separates the upper and lower lobes of the lungs?

Answer 16

Oblique/major fissure

Question 17

What does the horizontal fissure separate?

Answer 17

Right upper lobe from right middle lobe

Question 18

On the lateral CXR, what do you need to look for to tell the difference between the right and left hemi-diaphragms?

Answer 18

Which ribs the hemi-diaphragm abuts:

• Left= smaller/ non-magnified
• Right= larger/magnified

Question 19

What structure prevents the anterior left hemi-diaphragm from touching the anterior thorax?

Answer 19

Heart

Question 20

What is the retrosternal clear space?

Answer 20

Space between the chest wall and heart i.e. anterior mediastinum

Question 21

What are the 5 T’s that can fill the retrosternal space?

Answer 21

1) Terrible lymphoma
2) Thymoma
3) Teratoma
4) Thyroid
5) Throacic aortic aneurysm

Question 22

What is the retrotracheal clear space?

Answer 22

Space between the trachea and the T-spine

Question 23

What diseases can fill the retrotracheal clear space?

Answer 23

1) Vascular abnormalities
2) Esophageal disease
3) Lung cancer

Question 24

What is the retrocardiac space?

Answer 24

This is the normal clear “space” that is posterior to the heart on lateral CXR

Question 25

What diseases can fill the retrocardiac space?

Answer 25

1) Hiatal hernia
2) Esophageal disease
3) LV enlargement
4) Pneumonia

Question 26

What are the contents of the anterior mediastinum?

Answer 26

• Thymus
• Lymph nodes
• Fat
• Inframammary vessels

Question 27

What should you remember about a mass that crosses the midline on a CXR?

Answer 27

Likely NOT part of the lung b/c the lungs don’t communicate

Question 28

What shape should the AP window be on PA CXR?

Answer 28

Concave

Question 29

What is the cardiothoracic ratio?

Answer 29

Max diameter of heart vs. thorax

Should be less than 0.5 on PA CXR

Question 30

What should the relationship between the right and left hilar structures be?

Answer 30

Left is typically higher than right

Question 31

What should the relationship between the hemidiaphragms be?

Answer 31

Right is higher than left (b/c of liver)

Question 32

What is the sequence for reviewing a CXR?

Answer 32

1) Admin
2) Quality
3) Initial survey
4) Soft tissue
5) Bones
6) Mediastinum
7) Pleura spaces
8) Lungs