De Moya et al developed an Occult Pneumothorax (OPTX) score for grading the size of a pneumothorax associated with trauma. This can help determine if a chest tube will be required for managing the patient. The authors are from the University of Miami, Massachusetts General Hospital and the University of Southern California.

Requirement: horizontal/transverse imaging slice demonstrating the pneumothorax at its maximum extent


The transhilar axial plane is a coronal/frontal plane that goes through the hilum



(1) maximum distance along a line perpendicular to the chest wall across the largest air pocket in the hemithorax, in mm

(2) points assigned relative to the transhilar axial plane




all parts anterior to transhilar plane


any part posterior to the transhilar plane



OPTX score =

= (points for maximum diameter along perpendicular line) + (points for location relative to the transhilar axial plane)



• minimum score: around 11

• maximum score: > 90

• If the OPTX is > 30 then the positive predictive value for chest tube placement is about 80%.

• If the OPTX is < 20 then the negative predictive value for chest tube placement is about 70%.



• The area under the ROC curve was 0.72.

To read more or access our algorithms and calculators, please log in or register.