This retrospective study echoes REACT-2: pan-scan is low yield. The proportion of patients with clinically significant injury (CSI) involving at least 2 simultaneous body regions - head/neck| chest| abdomen/pelvis was 1 to 3%; 0.6% had CSI simultaneously in all 3 regions.
Why does this matter?
Pan-scan CT is prevalent at many trauma centers. Trauma surgeons want all injuries identified, because missed injuries are associated with increased morbidity and mortality. The downside is that thousands of patients have regions of the body scanned that the ordering clinician knows almost certainly do not have any serious injury, either for the sake of completeness or to appease trauma so they will admit the patient. A pan-scan CT is the radiation equivalent of around 300 CXRs. This is not trivial, and there is a real attributable risk of future malignancy to that amount of radiation. You need to read this classic NEJM review and this landmark Lancet study. Not to mention, a pan scan charge is at least $11,000.
Light 'em up
This was a retrospective study of 1236 patients who underwent CT head through pelvis for trauma. They determined what injuries they would deem "clinically significant" a priori. They looked at the number of CSIs divided by the number of total scans of three areas: head/neck, chest, and abdomen/pelvis. Overall, 11% of head/neck scans were positive; 8% of chest scans; and 5% of abdomen/pelvis scans. But if one looked at how many had both head/neck and chest, both were positive in only 2.8%; head/neck and abdomen/pelvis, 1.6%; chest plus abdomen/pelvis, 1.1%; all three regions simultaneously, 0.6% positive. This means that scanning multiple areas of the body is generally low yield and makes an argument for selective scanning. Thankfully, we already have much higher quality data that actually proves this point - see REACT-2.
Low Yield of Clinically Significant Injury With Head-To-Pelvis Computed Tomography in Blunt Trauma Evaluation. J Emerg Med. 2017 Oct 28. pii: S0736-4679(17)30742-4. doi: 10.1016/j.jemermed.2017.08.036. [Epub ahead of print]
Peer reviewed by Thomas Davis, MD.