Chest X-Ray Interpretation

Question 1

What mnemonic can be used to assess image quality?

Answer 1

RIPE
Rotation (medial aspect of clavicle equidistant from spinous processes
Inspiration (5-6 anterior ribs, lung apices costophrenic angles + lateral rib edges)
Projection (PA/AP)
Exposure (left hemidiaphragm visible to spine)

Question 2

What approach is used to interpret chest X rays?

Answer 2

ABCDE
Airway: trachea, carina, bronchi + hilar structures.
Breathing: lungs + pleura.
Cardiac: heart size + borders.
Diaphragm: inc. assessment of costophrenic angles.
Everything else: mediastinal contours, bones, soft tissues, tubes, valves, pacemakers + review areas.

Question 3

What are the true causes of tracheal deviation?

Answer 3

Pushing: large pleural effusion, tension pneumothorax.
Pulling: consolidation with associated lobar collapse.

Question 4

What can cause apparent tracheal deviation?

Answer 4

Rotation of the patient

so inspect clavicles to rule out presence of rotation

Question 5

Why is it more common for inhaled foreign objects to become lodged in the right main bronchus?

Answer 5

It is wider, shorter + more vertical

Question 6

What needs to be assessed about the hilar? What can variations be caused by?

Answer 6

Size: asymmetry raises suspicion of pathology.
Bilateral symmetrical enlargement: sarcoidosis.
Unilateral/asymmetrical enlargement: underlying malignancy.

Question 7

Why is the hilar an important landmark? What might cause abnormal positioning?

Answer 7

Site where descending pulmonary artery passes superior pulmonary vein.
Pushed: enlarging soft tissue mass
Pulled: lobar collapse

Question 8

How should you assess the lungs?

Answer 8

Divide each into 3 zones

Compare zones between lungs

Question 9

Which pathologies may cause the following:
Symmetrical changes in the lung fields
Increased airspace shadowing in a given area
Complete absence of lung markings

Answer 9

SC: pulmonary oedema
IA: consolidation/ malignant lesion
CA: pneumothorax.

Question 10

What does visible pleura indicate? What is this associated with?

Answer 10

Pleural thickening

Mesothelioma

Question 11

What is the absence of lung markings suggestive of?

Answer 11

Pneumothorax

Question 12

What causes increased opacity in the lungs?

Answer 12

Fluid (hydrothorax)

Blood (haemothorax)

Question 13

What is a tension pneumothorax? What are the signs of this?

Answer 13

increasing amount of air being trapped within the pleural cavity displacing mediastinal structures + impairing cardiac function.
SOB + Tracheal deviation

Question 14

In PA X-rays how much of the thoracic width should be occupied by the heart?

Answer 14

No more than 50%

Question 15

List 4 causes of cardiomegaly

Answer 15

Valvular heart disease
Cardiomyopathy
Pulmonary hypertension
Pericardial effusion

Question 16

What accounts for most of the hearts’ borders?

Answer 16

Right: Right atrium
Left: Left ventricle

Question 17

What is the cause of reduced definition of the right and left heart borders?

Answer 17

Right: right middle lobe consolidation.
Left: lingular consolidation

Question 18

Why is the right hemidiaphragm usually higher than the left?

Answer 18

Due to the underlying liver (indistinguishable from hemidiaphragm)

Question 19

What leads to the right diaphragm lifting and visibly separating from the liver? What causes this?

Answer 19

Free gas: air accumulates under the diaphragm

Bowel perforation

Question 20

Name a condition that can give the false impression of free gas under the diaphragm (pseudo-pneumoperitoneum)? How?

Answer 20

Chilaiditi syndrome
involves abnormal position of the colon between liver + diaphragm- looks like free gas under the diaphragm (bowel wall + diaphragm become indistinguishable due to their proximity)

Question 21

What are costophrenic angles formed between? Describe these in a healthy individual

Answer 21

Dome of each hemidiaphragm + lateral chest wall.
Clearly visible
Acute angle

Question 22

What is the term for loss of the costophrenic angle? What causes this? What may this develop secondary to?

Answer 22

Costophrenic blunting.
Fluid or consolidation in the area.
Lung hyperinflation in COPD can cause diaphragmatic flattening + subsequent loss of the acute angle

Question 23

Where is the aortic knuckle? What can cause reduced definition?

Answer 23

Left lateral edge of the aorta as it arches back over the left main bronchus.
Reduced definition: aneurysm.

Question 24

Where is the aortopulmonary window? What can cause loss of this?

Answer 24

Between the arch of the aorta + the pulmonary arteries.

Lost: mediastinal lymphadenopathy (e.g. malignancy).

Question 25

What abnormalities do you look for in the bones?

Answer 25

Fractures | Lytic lesions

Question 26

Name an abnormality that may be seen in the soft tissue

Answer 26

Large haematoma

Question 27

Describe the appearance of tubes, artificial heart valves and pacemakers on a CXR

Answer 27

Tubes + cables: radio-opaque lines (e.g. central line, ECG cables). Artificial heart valves: ring-shaped structures within heart region (e.g. aortic valve replacement). Pacemaker: radio-opaque disc or oval in the infraclavicular region connected to pacemaker wires positioned within the heart.

Question 28

Where are the review areas in which pathology is often missed?

Answer 28

``` Lung apices Retrocardiac region Behind the diaphragm Peripheral region of the lungs Hilar regions ```