Hemithorax Whiteout – CXR

Table of Contents

Table of Contents

Published March 2021

Daniel Gergen, MD1 , Samantha King, MD2

1 Fellow, Pulmonary and Critical Care Medicine, University of Colorado, 2 Chief Medical Resident, Internal Medicine, University of Colorado.


  1. Use tracheal deviation either toward or away from a large lung opacity on a CXR to narrow the differential of the lesion.

Teaching Instructions

Plan to spend 5-10 minutes familiarizing yourself with the animations of the PowerPoint and the key findings of this chest X-ray.

Instructions: Present the image either by expanding the window (bottom right) in a browser or downloading the PowerPoint file (downloading is recommended.  Have the image pulled up in presenter mode before learners look at the screen to avoid revealing the diagnosis.  Ask a learner to provide an overall interpretation.  Then advance through the animations to prompt learners with key questions and reveal the findings, diagnosis, and teaching points.  You can go back to prior graphics and questions by using the back arrow or scrolling back on the mouse wheel.

Official CXR Read:
Left Image: Complete whiteout of the left hemithorax. The heart is obscured. The right lung is grossly clear. There is a small right pleural effusion. No right pneumothorax. The left diaphragm is elevated due to the collapse of the left lung.
Right Image: Right hemithorax is now completely opacified consistent with interval enlargement of the very large right pleural effusion.  Interval worsening of patchy left lung opacities with air bronchograms which may represent aspiration, pneumonia, and/or edema. No significant pneumothorax.


Left Image: Stage IV adenocarcinoma w/ massive hemoptysis and obstruction of L main bronchus resulting in left lung collapse.

Right Image: Cirrhosis complicated by large hepatic hydrothorax.

Teaching (Approach to Large Lung Opacities):

Position of the trachea, gastric bubble, and mediastinum position? If the trachea is shifted towards the whiteout then there is volume loss. If the trachea is shifted away from the whiteout then there is volume gain/mass effect.

Differential based on change of structure positions:

Towards whiteout (volume loss)MidlineAway from whiteout (mass effect)

-Mainstem obstruction


-Pulmonary agenesis/hypoplasia


-Pleural mass

-Chest wall mass

-Pleural effusion

-Intra-pulmonary mass

-Diaphragmatic hernia

Here is another example of lung whiteout differentiated by tracheal deviation.

Presentation Board

Take Home Point

  1. Determine if the trachea, gastric bubble and cardiac silhouette are shifted toward or away from any large lung opacity to better narrow the differential to a volume losing process or volume-occupying process. 

Goodman, L. R. (2019). Felson's Principles of Chest Roentgenology E-Book: A Programmed Text. Netherlands: Elsevier Health Sciences.

Brandon Fainstad


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