Comparing lung diseases.

Question 1

Pneumonia vs pleural effusion.

Answer 1

Pneumonia - inflammatory exudate is inside the alveoli, pleural space clear. Infectious.
Pleural effusion - transudate (cirrhosis, CHF) or exudate (TB, malignancy) at base of pleural space with meniscus sign.

Question 2

Lower lobar pneumonia vs pleural effusion.

Answer 2

Lobar Pneumonia - confined to only one lobe with a visible diaphragm and no meniscus sign, generally not very dense.
Pleural effusion - fluid at the bottom but does not have to be one whole lobe, meniscus sign but no diaphragm outline because fluid here is very dense.

Question 3

Hyperinflated lungs COPD vs pneumothorax

Answer 3

Hyperinflation - flattened diaphragm and ‘barrel-chest’ with lung marking over whole chest.
Pneumothorax - hyperlucent affected side with reduced lung markings and visible edge of collapsed lung.

Question 4

Horner’s Syndrome (Pancoast tumour) vs occulomotor nerve lesion.

Answer 4

Horner’s Syndrome - impingement of the sympathetic chain. Ptosis (tarsal muscle with sympathetic), anhydrosis and miosis (constriction seen - dilator pupillae lost with sympathetics) seen.

Occulomotor nerve lesion - motor and parasympathetic function lost leading to ‘Down and Out’ position from paralysis of all muscles except lateral rectus and superior oblique. Ptosis seen also (levator palpebrae superioris lost). Blown pupil here rather than constricted because lost parasympathetic sphincter pupillae.