Blunt thoracic aortic injury (BTAI) is one of those high-acuity, low-occurrence events that trauma professionals cannot afford to miss. These injuries are a ticking time bomb that is just waiting to blow up your patient.
Diagnostic techniques have evolved over the years. Back in the old days (before CT angiography), we always performed a screening chest x-ray and used the “pager test.”
In those days, the x-rays were processed on celluloid and placed on a light box on the wall. We would place our pager against the film. If the aortic arch was wider than the length of the pager, the patient had a wide mediastinum, and we had to rule out BTAI. And in those days, contrast angiography was the only test available. This was a major production, and we did lots of them. Most were negative.
My, how we have advanced. We have now added contrast-enhanced CT (CECT) and transesophageal ultrasound (TEUS) to our armamentarium. The question now is, what is the best screening test?
A group of Italian clinicians performed a systematic review and meta-analysis of these modalities to determine which had the best diagnostic accuracy.
Here are the factoids:
- The authors pooled 77 studies evaluating chest x-ray, conventional angiography, CECT, and TEE
- This table compares the results for each:
| Modality | # studies | Sensitivity | Specificity | AUC (ROC) |
| Chest x-ray | 11 | .87 | .56 | .85 |
| Angiography | 16 | .97 | .99 | 1.00 |
| CECT | 34 | .98 | .97 | 1.00 |
| TEUS | 16 | .94 | .99 | .99 |
Bottom line: Basically, angiography, CECT, and TEUS were equivalent. Chest x-ray had poor sensitivity and specificity. So back in the day, we probably made a lot of errors.
When multiple tests have similar performance, the preferred test should be chosen based on availability, ease of use, and bonus information the study may provide. Hands down, the winner is contrast-enhanced chest CT. This is commonly performed in major trauma patients already and provides a wealth of diagnostic information. It is well-tolerated and relatively inexpensive.
The final answer, then, is contrast-enhanced CT. And I would add one little extra. As I’ve written about previously, our current criteria for identifying blunt carotid and vertebral injury (BCVI) miss about 25% of injuries. They are readily seen on CECT, though. It is relatively simple to modify the CECT chest protocol to capture the neck arteries with the same contrast dose. I strongly recommend updating your imaging protocol so that, whenever you obtain a CECT chest, the CECT neck is automatically added.
Reference: Defining the criterion standard for detecting blunt traumatic aortic injuries: A systematic review and meta-analysis of diagnostic test accuracy. J Trauma Acute Care Surg. 2025 Aug 1;99(2):279-288. doi: 10.1097/TA.0000000000004642. Epub 2025 May 20. PMID: 40390169.
