Radiology #5: Sulky
- nicholaschapmannz
- Jul 9
- 1 min read
Updated: Aug 2
The Patient
A 30 year old patient presents after being stabbed in the right upper back. A LODOX image is taken with the patient supine. You magnify the chest and see the following image:
The Pictures
What do you think?
click to reveal the answer
There is a right pneumothorax.
If you look closely you can see a pleural line (white arrows) and beyond it the absence of any lung markings.
We're lucky to even see that however, because the sensitivity of a supine chest x-ray is far lower than that of an erect chest x-ray (50% vs 92%) [1]. This is because the air tends to collect anteriorly when supine, rather than apically.
On a supine film, the first hint of air in the pleural space comes in the form of a "deep sulcus sign", seen here marked with a red arrow. This is an important finding, because we often assess trauma patients when they're supine. Penetrating trauma is often seen first on the LODOX, and blunt trauma usually comes hand-in-hand with spinal precautions. The diagram below demonstrates well why the deep sulcus sign tends to occur [2]:
So - in the supine patient, look twice at those costodiaphragmatic recesses.
Thanks to Dr Ryoko Kinukawa for submitting this case.
References
click to see references
[1] Omar HR, Abdelmalak H, Mangar D, et al. Occult pneumothorax, revisited. J Trauma Manag Outcomes. 2010: 4:12. doi: 10.1186/1752-2897-4-12.
[2] Skalski M. Pneumothorax distribution - illustration. Radiopaedia [internet]. 2013. Accessed 15 May 2025. Available from: https://radiopaedia.org/cases/pneumothorax-distribution-illustration-1?lang=us
