Mnemonics for a unilateral hyperlucent hemithorax include:
- CRAWLS
- SAFE POEM
- ACROSSS
Mnemonics
CRAWLS
- C: contralateral lung increased density (e.g. supine pleural effusion)
- R: rotation
- A: air (pneumothorax)
- W: wall (chest wall mass, mastectomy, polio, Poland syndrome, surgical removal of the pectoralis major muscle)
- L: lungs (airway obstruction, emphysema, Swyer-James syndrome, unilateral large bullae, large pulmonary embolus)
- S: scoliosis
SAFE POEM
- S: Swyer-James syndrome
- A: agenesis (pulmonary)
- F: fibrosis (mediastinal)
- E: effusion (pleural effusion on the contralateral side)
- P: pneumonectomy/pneumothorax
- O: obstruction (airway)
- E: embolus (pulmonary)
- M: mucous plug
ACROSSS
- A: air (pneumothorax), artery (pulmonary aplasia or hypoplasia)
- C: chest wall (mastectomy, polio, Poland syndrome)
- R: rotation
- O: obstructive causes (airway obstruction, foreign body, unilateral emphysema, large embolus)
- S: scoliosis
- S: surrounding (increased density in contralateral lung, e.g. pleural effusion in the opposite lung in a recumbent patient)
- S: Swyer-James syndrome