Chest X-Ray breakdown: how to approach a white-out 

A male in his 50s presents to the Emergency Department with breathlessness and has a chest X-Ray. What does it show?
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ASSESSING A ‘WHITE-OUT’
👨🏽‍💻This film is all about being able to pick apart the different causes of a ‘white-out’, ie a completely opacified hemithorax
👨🏽‍💻We can divide the different causes into three categories:
1️⃣ MEDIASTINUM/TRACHEA PULLED TOWARDS WHITE-OUT - LOSS OF VOLUME
▫️Complete collapse of lung - consider foreign body, mucus plugging and an obstructing lung cancer
▫️Pneumonectomy can look identical - here look out for surgical clips
2️⃣ MEDIASTINUM/TRACHEA NOT CHANGED IN POSITION
▫️Consolidation - usually this is not associated with a change in volume
▫️In rare cases the hemithorax may be completely occupied by tumour
3️⃣ MEDIASTINUM/TRACHEA PUSHED AWAY FROM WHITE OUT - INCREASE IN VOLUME
▫️Large pleural effusion
▫️Again in rare cases the hemithorax may be completely occupied by tumour
👨🏽‍💻I was taught this strategy as a medical student and it’s still something I use to this day! In this case the trachea and mediastinum are pushed away from the white-out meaning the most likely pathology is a pleural effusion. Now remember in reality the pathologies can overlap and there will be cases we see a mixture of lung consolidation, collapse and pleural effusion
👨🏽‍💻Here an ultrasound was done to confirm the pleural effusion - here we would see an ‘anechoic’ structure on ultrasound, ie black, relating to fluid. Ultrasound is a great next step as it helps to confirm a pleural effusion. The effusion was drained under ultrasound guidance
👨🏽‍💻In this case the white-out was mostly due to pleural effusion whilst there was also an underlying metastasis from prior oesophageal cancer. The effusion was likely a malignant effusion however cytology results on the fluid in this case were negative - worth remembering that cytology on pleural effusion is not completely sensitive and there may be false negatives. The diagnosis was then made by biopsying the metastasis under CT guidance
▫️Hopefully this case will give you a strategy the next time you see a ‘white-out’ on chest X-Ray
🔻@theradiologistpage