Abnormal Chest X-ray

Question 1

silhouette sign

Answer 1

Radiopacity which causes obliteration of part of or all of the heart border

Question 2

can you tell the difference btwn hemorrhage or PNA on a chest x-ray?

Answer 2

No! Just see an opacity.

Question 3

air bronchogram sign

Answer 3

when you have fluid in the alveoli and therefore you can see the air in the bronchi

Question 4

5 mechanisms of volume loss in the lung

Answer 4

1. resorption of air as a result of obstruction
2. relaxation o flung due to air/fluid in pleural space
3. scarring causing lung retraction
4. decreased surfactant
5. hypoventilation in CNS depression or pain

Question 5

How do the fissures change in event of lung collapse? (direct signs)

Answer 5

RUL: minor fissure superior/major anterior
RML: minor down/major superior
RLL: major posterior/inferior - spine gets lighter
LUL: major anterior
LLL: major - thick opaque straight line, spine gets lighter

Question 6

what are some direct signs of lung collapse?

Answer 6

fissure movement and crowding of the bronchovascular markings in the affected lobe

Question 7

what are some indirect signs of collapse?

Answer 7

1. right hilum is higher than left
2. deviation of trachea to side of collapse
3. cardiac displacement to side of collapse
4. narrowing of the rib cage
5. compensatory overaeration of adjacent lung

Question 8

what are the 2 things that cause straight lines on an xr?

Answer 8

1. fluid-air levels

2. fissures

Question 9

name 4 factors of lung disease to identify on xr

Answer 9

1. interstitium: linear, discrete (nodules), or combo
2. alveoli: filled with air or fluid
3. pattern: nodular or diffuse
4. timing: acute or chronic

Question 10

how can you see a pneumothorax on xray

Answer 10

it will be blacker - then the lung

Question 11

what is the most frequent sign of mediastinal disease

Answer 11

widening

Question 12

what is a straight line seen in the mediastinum represent

Answer 12

hiatal hernia

Question 13

how can you see CHF on an xray

Answer 13

1. cardiac changes
   - left border of the heart moves laterally
   - cardiac apex moves anterolateral
   - cardiothoracic ratio > 0.50
2. Kerley B lines
3. Alveolar edema
4. vasculature: lower lobe vessels larger than upper

Question 14

when would you decide to perform a CTA

Answer 14

when you have a positive pretest probability - NPV 99 %

Question 15

describe Well’s criteria

Answer 15

3 point - suspected DVT
1.5 points - tachy, recent sx, previous PE/ DVT
1 point - hemoptysis or malignancy

Question 16

VQ perfusion scan problems

Answer 16

very difficult to read therefore alot of error

Question 17

what is used for pretest probability of VQ scans

Answer 17

PIODPED II - high probability, nondiagnostic, low probability