Resp20 - The Chest X-Ray

Question 1

2 different projections of an X-Ray

Answer 1

1. ) PA Projection - posterior to anterior, gold standard
   - x-ray source behind the patient fired unto the patient’s back and hits a screen in front of the them
   - patient is usually standing
2. ) AP Projection - anterior to posterior
   - done when the patient is too unwell to stand so its usually done sitting on their beds
   - heart looks enlarged, cardiothoracic ratio inaccurate

Question 2

4 features of lung volumes in an X-ray

Inspiratory Phase
Normal Inspiration
Incomplete Inspiration
Exaggerated Expansion

Answer 2

1. ) Inspiratory Phase - image is taken whilst the patient is breathing in
2. ) Normal Inspiration - can see 5th-7th anterior ribs at the mid-clavicular line
3. ) Incomplete Inspiration - problems w/ the image
   - the heart looks larger than it should be
   - increased lung markings
4. ) Exaggerated Expansion - can see > 7 anterior ribs
   - occurs in emphysema (COPD) due to hyperinflation
   - often also seen with a flattened diaphragm

Question 3

ABCDE approach of looking at an x-ray image

Answer 3

1.) Airway - trachea, carina, right and left main bronchus

2. ) Breathing - lungs should be expanded and similar in volume in both side, apicies and zones are symmetrical
   - lateral margins, hemidiaphragms, cardiac borders, costophrenic angle
3. ) Circulation - mediastinum, aortic knuckle/knob/arch, pulmonary vessels, hilar structures
   - heart borders: R = RA, L = LV, superior = LA
   - cardiothoracic ratio should be < 50% in PA projection
4. ) Diaphragm/Dem Bones
   - gastric bubble in left diaphragm, nodules
   - fractures, dislocations, masses

5.) Everything Else - review areas

Question 4

Review areas in a chest X-ray

3 Main
3 Others

Answer 4

1. ) Apices - pneumothorax
2. ) Behind the Heart - consolidation or mass
3. ) Below the Diaphragm - pneumoperitoneum or mass
4. ) Others - thoracic inlet, paratracheal stripe, AP window

Question 5

3 Signs in an CXR

Answer 5

1. ) Silhouette Sign - adjacent strucutres of differing densities form a crisp silhouette
   - loss of this contour can locate pathology and suggests consolidation or a mass
2. ) Meniscus Sign - crescent shaped contour between air and fluid
   - occurs w/ pleural effusions in upper border
3. ) Mediastinal Shift - tracheal deviation to one side
   - push: deviates away from an increase in pressure
   - pull: deviates towards a decrease in pressure

Question 6

6 specific CXR findings

Pneumothorax
Pleural Effusion
Consolidation
Space Occupying Lesion
Lobar Collapse
Cardiothoracic Ratio

Answer 6

1. ) Pneumothorax - visible pleural edge w/ lung markings not visible beyond this edge
2. ) Pleural Effusion - uniform white area w/ loss of costophrenic angle and obscured hemidiaphragm
3. ) Consolidation - filling of alveoli with stuff
   - pus=pneumonia (most common), blood=haemorrhage, fluid=oedema, cells=cancer
   - dense opacification w/ volume preserved +/- increased
4. ) Space Occupying Lesion - nodule (<3cm) or mass
   - single = primary carcinoma, mutiple = metastases
   - can also be benign, inflammatory, or congenital
5. ) Lobar Collapse - volume loss within lung lobe
   - elevation of ipsilateral hemidiaphragm
   - pull mediastinal shift towards side of atelectasis

6.) Cardiothoracic Ratio - normal = <50% in PA image