Unilateral hyperlucent lung.

Sir,

I read with great interest the review article by Singh et al.[1] about unilateral hyperlucent lung and their interesting, unusual causes.

As they mentioned, this appearance can be a result from a wide variety of technical or diseases, so I decide to write a quick, simple approach based on its etiology for this entity.

In case of any finding regarding of unilateral hyperlucency on chest X-ray first categorized it as positional or pathological causes. Thus if:

Positional (rotational): Turn toward film (or away of the beam) makes that hemithorax hypertranslucent. For example when the patient is turned to the left, the left side will be hypertranslucent

Pathological or (nonrotational): When rotation isn’t thought to be the cause.

In these types there are two helpful mnemonics:

SAFE POEM

S: Swyer-James syndrome

A: Agenesis (pulmonary)

F: Fibrosis

E: Effusion (pleural effusion on the contralateral side)

P: Pneumonectomy/pneumothorax

O: Obstruction

E: Pulmonary embolus

M: Mucous plugging.

CRAWLS

C: Contralateral pleural effusion

R: Rotation

A: Air, e.g., pneumothorax

W: Wall, e.g., chest wall mass, polio, mastectomy, and Poland syndrome

L: Lungs airway or vascular obstruction, foreign body aspiration, Swyer–James syndrome, accidental bronchial endotracheal tube intubation, congenital lobar overinflation, bullae, obliterative bronchiolitis, bronchial atresia, large pulmonary embolus (Westermark sign), congenital pulmonary artery hypoplasia, pulmonary artery stenosis, Blalock Taussig shunt

S: Scoliosis.[2]

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.