Chest X ray

Question 1

Cardio-thoracic ratio

Answer 1

• must be less than 50% in a PA xray
• can’t comment in AP x-ray

Question 2

What does the periphery of the lungs look like in a normal CXR?

Answer 2

Should not see many lung markings.

if you do it may show disease of the air spaces or interstitium.

Question 3

What does the edge of the lung look like in pneumothorax?

Answer 3

Sharp edge

Question 4

What would blunting of the costo-phrenic and cardio-phrenic angles suggest?

Answer 4

Effusion

Question 5

Systematic approach to CXR

Answer 5

• check patient details and date of xray
• Look at cardio-thoracic ratio in PA xray
• check if trachea is central
• check for mediastinal position
• check for mediastinal contours (stuff like the arotic arch, pulmonary arteries etc)
• check the hila of the lungs
• now look at the lungs, comparing both sides, working your way down
• check periphery of the lungs: should be no lung markings
• check for pneumothorax- radiolucent, would see sharp line at edge of the lung
• look at cardiophrenic and costophrenic angles, check for blunting
• check there’s no free air under hemidiaphragm
• check bones and soft tissue

Question 6

Useful pneumonic to summarise xray findings

Answer 6

Question 7

Findings of pneumothorax

Answer 7

• you need to disntinguish between the air in the lung and air in the pleural cavity- find the edge of the lung (shown by arrow)
• partial leftsided lung collapse

Question 8

Causes of pneumothorax

Answer 8

Question 9

Findings of consolidation

Answer 9

• look for area of whiteness
• look at the borders of the area. if they are well-demarcated it’s more likely to be effusion or an area of collapse
• if it’s not well-demarcated it’s more likely to be a consolidation, fibrosis or some infiltrative condition

Question 10

Findings of mass lesions (eg coin lesion)

Answer 10

• discrete area of whiteness in lung field
• has well demarcated edges
• coin lesion

Question 11

Causes of mass lesions

Answer 11

• benign or malignant masses
• infection eg TB, pneumonia, abscess, hyatid cyst
• infarction
• rheumatoid nodule

Question 12

Bihilar lymphadenopathy: findings and causes

Answer 12

• hilar edges can either be rgeular or irregular
• need to confirm with lateral xray. if so then do bronchoscopy

Causes:

• neoplastic causes- spread from a bronchial carcinoma or primary lymphoma
• infective eg TB
• sarcoidosis (usually bilateral)

Question 13

Hyperinflated lungs

Answer 13

-common sign of COPD

Xray:

• count anterior ribs. should be more than 7
• look at shape of diaphragm- not concave. often flat or scalloped. more reliable than former method.

Question 14

Common cause of cardiomegaly and xray findings

Answer 14

• common cause is left ventricular failure leading to enlargement
• can’t comment if it’s an AP xray

Question 15

What rib level does the diaphragm lie at?

Answer 15

6th rib anteriorly

Question 16

What makes up the right border of the heart on a PA xray?

Answer 16

Only the right atrium.

Because the right ventricle sits anteriorly so doesn’t have a border on a PA film