This is a good study of ultra-low-dose CT in the acute trauma setting. These types of studies that quantitatively evaluate things that would seem intuitive (CT is better than radiographs for fracture detection) are very important. This is especially true when including a new variable like a dramatic reduction in the radiation dose. This study adequately shows the value of ultra-low-dose CT in the evaluation of acute trauma of the extremities.

The major strengths of this study are its large sample size and its very limited exclusion criteria. Another major strength is the inclusion of both the image acquisition time and time to preliminary report, as using the ultra low dose CT in the acute setting would not be practical if it was time intensive. I also like that the authors included an orthopedic surgeon’s input on how the increased information from the CT affected patient treatment. The data acquisition and analysis appear valid, and support the study’s conclusions that this exam adds value without a significant increase in radiation dose.

The major limitations of this study are acknowledged by the authors. The most important variable that was not measured in this study is the cost of the CT versus the cost of the radiographs. This does provide an opportunity to evaluate its cost-effectiveness in the future. I cannot think of any study limitations that the authors did not specifically address.

I have no particular recommendations for improvement of the study or manuscript.