To Scan or Not to Scan: Trauma Imaging in the Age of the Pan-Scan

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Trauma imaging has never been more accessible, and the pan‑scan often feels like the fastest path to certainty. In this edition of our resident journal club, we pair and review two articles regarding trauma CT utilization - REACT-2 and Ather et al, with a hope of exploring the question of when whole-body CT improves care vs when selective imaging can be equally as effective.

Sierink JC, Treskes K, Edwards MJ, et al. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial. Lancet. 2016;388(10045):673-683. doi:10.1016/S0140-6736(16)30932-1

Ather S, Nash K, Alexander J, et al. CT scan evaluation of injuries in patients over 60 years old following a fall from standing height. Emerg Radiol. 2025;32(5):765-772. doi:10.1007/s10140-025-02373-y

Introduction

Imaging is a cornerstone of part of trauma evaluation in the Emergency Department. In the trauma bay, where the priority is rapidly identifying life-threatening injuries, it can be easy to default to the pan-scan. In contrast, for the geriatric patient with a ground level fall, we often start with plain films. Yet even in this population, CT use has been steadily increasing, driven by concerns about missed injuries, anticoagulation, and the limitations of CXR – a trend highlighted in one of the studies reviewed in this post.

For background, let’s talk briefly about CT utilization and how dramatically it has increased over the last decade. Between 2014 and 2021, CT volumes per ED encounter rose by 35.5% at a level I trauma center and 74.6% at a level III trauma center (1). In the Medicare population, CT utilization per 1,000 beneficiaries increased by 153% between 2004 and 2016, outpacing growth in radiography and ultrasound (2). For head CT specifically, the total number of scans obtained in US EDs doubled from approximately 7.8 million in 2007 to nearly 16 million in 2022 (3). Given these trends, as well as rising healthcare costs, longer ED length of stays, increased boarding, and an ever increasingly older and sicker population, EM physicians’ CT utilization is often measured, often times with emphasis on more judicious (read: less) CT utilization. 

The two studies reviewed here challenge us to think about critically about trauma imaging, raising questions such as “Do more CTs actually improve care of our patients, or do they just make us feel better?” and “What are the consequences of over-scanning?”. We chose this pairing - the REACT‑2 trial and the Ather et al. elderly falls study - because together they offer two very different but complementary perspectives on CT scanning versus selective imaging.

Together, these studies frame a conversation that every EM resident needs to have: When should we scan? What should we scan? And does more imaging actually mean better care? Below, we break down each study’s design, results, and clinical implications, then synthesize what they collectively teach us about matching imaging strategy to the patient in front of us.

Article 1: REACT-2 Trial

It's 2 AM, a trauma activation rolls in, and before you even know it the patient is heading off for a pan-scan. Sound familiar? But, does this immediate whole-body CT (WBCT) actually improve outcomes compared to selective imaging? The REACT-2 trial tackled this question head-on — and the answer might surprise you. 

  • Title: Immediate Total-Body CT Scanning Versus Conventional Imaging and Selective CT Scanning in Patients With Severe Trauma (REACT-2)

  • Published: The Lancet, August 2016

  • Design: International, multicenter, randomized controlled trial across 5 Level I trauma centers (4 in the Netherlands, 1 in Switzerland)

Background

Prior to this study, retrospective data had suggested a mortality benefit with whole body CT in moderate to severe trauma. Based on this, whole body CT had become increasingly popular in trauma evaluation and resuscitation. REACT-2 was the first randomized control trial to directly compare immediate whole body CT to the standard ATLS approach.  

Methods

  • Randomized 1,083 adult trauma patients with suspected severe injuries to one of two groups:

  • Immediate total-body CT (iTBCT): Contrast-enhanced head-to-pelvis CT during the primary survey (without X-rays or FAST first)

  • Standard work-up (STWU): Conventional imaging (X-rays, FAST) followed by selective CT scanning as clinically indicated

  • Inclusion criteria: patients with compromised vital signs, clinical suspicion of life-threatening injuries, or high-risk mechanisms

  • Exclusion criteria: patients needing immediate CPR or emergent surgery 

RESULTS

Primary outcome — In-hospital mortality:

  • iTBCT group: 16% (86/541)

  • Standard work-up group: 16% (85/542)

  • No significant difference (p = 0.92)

Key secondary findings

  • No mortality difference in subgroup analyses of polytrauma patients or those with traumatic brain injury

  • Time to diagnosis was faster with iTBCT: 50 min vs. 58 min (p = 0.001)

  • Time to end of imaging was faster with iTBCT: 30 min vs. 37 min (p < 0.0001)

  • Radiation exposure was higher in the iTBCT group: 20.9 mSv vs. 20.6 mSv (p < 0.0001)

  • Notably, 45% of patients in the standard work-up group received a radiation dose lower than the minimum dose in the iTBCT group

Conclusions

  • The pan-scan does not improve mortality over a selective imaging strategy in the general severe trauma population

  • It does get you to a diagnosis faster — which can matter in a busy trauma bay

  • The radiation difference is real but modest; the bigger issue is that nearly half of selectively imaged patients end up getting a full-body scan anyway

  • Clinical judgment still matters. A selective approach — using history, exam, X-rays, and FAST to guide CT — performs just as well as whole-body scanning

  • The possible exception: polytrauma and TBI patients may benefit from an upfront pan-scan based on subgroup analyses

Limitations

  • The trial was conducted at high-volume European Level I centers with CT scanners in or adjacent to the trauma bay - a luxury that not all centers have 

  • About 46% of the standard work-up group ended up getting CT of all body regions anyway — essentially a pan-scan by the end of their workup – arguably the study’s biggest limitation

  • Randomization was not concealed, and blinding was not possible

  • About 15% of patients were excluded after randomization

  • One-third of patients ended up having a low injury severity score, meaning a large portion of the population was not very sick

  • The ACEP 2024 Clinical Policy on blunt trauma noted these methodologic limitations and considered REACT-2 indirect evidence for hemodynamically stable patients specifically

Clinical Takeaways

The CT scanner is fast and convenient, but not a magic bullet. For most trauma activations, selective imaging guided by clinical findings performs just as well. Save the pan-scan for the patients who truly need it - like the polytrauma patient or the obtunded patient where your clinical exam is unreliable.

Article 2: Elderly Falls Study (Ather et. al) 

It’s 5 hours into your shift. You’ve just finished getting your rollover MVC settled, and they’ve been returned to their room after their pan scan. Now, a 70 year old lady is rolling in with EMS, and you hear someone say she had an unwitnessed fall at the SNF…and she takes Eliquis for Afib. You’re already pressing the CT button again.

  • Title: CT scan evaluation of injuries in patients over 60 years old following a fall from standing height

  • Published: Emergency Radiology, Aug 21, 2025

  • Design: UK retrospective observational study at a regional major trauma center with over 135,000 annual attendances

Background

Falls from standing height are one of the most common reasons older adults present to the emergency department. Rib fractures increase mortality and pneumonia risk. Chest X-ray (CXR) is frequently used as first-line imaging but has poor sensitivity for rib fractures, pneumothorax, and hemothorax compared to CT. No standardized recommendations exist for which type of imaging to obtain in this demographic of patients.

Methods

  • Inclusion: all CT chests for patients >60 following a fall from standing height, March 2019- February 2020

  • Exclusion: Patients scanned for other reasons (e.g., pulmonary embolism, high-energy trauma)

  • Standardized triage pathway for CT thorax, triggered by:

    • Raised respiratory rate (>24)

    • Low oxygen saturations (<95% on air)

    • Cardiorespiratory comorbidities

    • Anticoagulation use

    • Fall onto an object

    • Impaired clinical assessment (cognitive impairment, distracting injury, intoxication)

    • Senior clinician suspicion of significant injury

  •  Contrast-enhanced CT of the chest, abdomen, and pelvis was added when intra-abdominal injury was suspected

overall Results

  • 349 patients met inclusion criteria out of an initial pool of 564

  • Mean age: 83 years; 59% female

  • 204 underwent non-contrast CT chest; 145 underwent contrast-enhanced CT chest/abdomen/pelvis

Thoracic ct findings

  • 187 patients (54%) had at least one acute finding

  • 170 patients (49%) had one or more rib fractures

  • 16 patients (5%) had radiological flail segments

  • 44 patients (13%) had a hemothorax

  • 30 patients (9%) had a pneumothorax

  • 31 patients (9%) had lung contusions

  • 23 patients (7%) had other acute fractures (sternal, humeral, clavicular, scapular, thoracic vertebral)

  • 11 patients had incidental acute medical findings (PE, aspiration pneumonia, heart failure)

CXR VS. CT Comparison:

  • 147 patients had both CXR and CT

  • 70 patients had rib fractures on CT, but only 15 were visible on CXR

  • CXR sensitivity for rib fractures: 21%; specificity: 100%

Abdonminal-pelvic ct findings:

  • Only 23 of 145 patients (16%) had an acute traumatic finding

  • Serious abdominal organ injuries (splenic laceration, intra-abdominal hemorrhage) found in just 7 patients — all had clinical signs of abdominal injury or active hemorrhage

  • Musculoskeletal findings: 5 lumbar vertebral fractures, 6 pelvic fractures, 2 femoral fractures

KEY DISCUSSION POINTS

  • Over half of patients scanned had acute thoracic findings, confirming the fragility of this population

  • CXR missed nearly 80% of rib fractures, reinforcing CT as the superior modality when thoracic injury is suspected

  • Serious abdominal injuries were rare and occurred only in patients with clinical signs

  • screening CTAP unnecessary without specific clinical suspicion

  • CXR alone may lead to underestimation of complication risk if true extent of injuries/rib fractures is not known

  • Accurate diagnosis facilitates better pain management and informs disposition — particularly important in elderly patients who may struggle to communicate symptoms

lIMITATIONS

  • Retrospective design

  • Single-center study

  • Patient selection → clinical suspicion for thoracic injury was part of initial selection, which doesn’t fully get at our question of imaging selection in ALL elderly falls, where CXR remains standard screening image of choice

Conclusion

  • Patients over 60 who fall from standing height can develop significant thoracic injuries, most commonly multiple rib fractures

  • CT thorax is superior to CXR for detecting these injuries, with meaningful implications for risk stratification, pain management, and clinical decision-making in those whom there is clinical concern for thoracic trauma

  • Contrast-enhanced abdominal-pelvic CT should be reserved for cases with specific clinical indicators of intra-abdominal injury or hemodynamic compromise

  • Further prospective trials comparing CT- versus CXR-guided management are needed to inform national imaging guidelines for elderly fall patients

Clinical takeaways

Don't underestimate the "simple fall" in an elderly person. When a thoracic injury is suspected, especially in patients where obtaining a thorough history and physical exam is difficult, a CXR is not always enough. In this population, especially in those on anticoagulation or with underlying cardiopulmonary comorbidities, we should have a lower threshold to obtain a CT chest to assess for injuries.

Synthesis & final thoughts

In summary, REACT‑2 shows that in high‑acuity trauma, immediate whole‑body CT does not improve mortality compared to a selective imaging strategy. It may speed up diagnosis, but it does not change survival — reinforcing that pan‑scanning should be reserved for patients whose exam is unreliable or whose injuries are truly diffuse.

For Ather et al., elderly patients with ground‑level falls frequently sustain significant thoracic injuries that CXR misses. CT of the thorax meaningfully improves detection and risk stratification. However, extending imaging to the abdomen and pelvis adds radiation, cost, and incidental findings without clear benefit unless clinical signs point toward intra‑abdominal injury.

Our takeaway: the pan‑scan is a tool, not a default.

The best imaging strategy is the one tailored to the patient in front of you — guided by mechanism, exam, reliability of assessment, and the specific clinical questions you need answered.

rEFERENCES

  1. Poyiadji N, Beauchamp N 3rd, Myers DT, Krupp S, Griffith B. Diagnostic Imaging Utilization in the Emergency Department: Recent Trends in Volume and Radiology Work Relative Value Units. J Am Coll Radiol. 2023 Dec;20(12):1207-1214. doi: 10.1016/j.jacr.2023.06.033. Epub 2023 Aug 4. PMID: 37543154.

  2. Selvarajan SK, Levin DC, Parker L. The Increasing Use of Emergency Department Imaging in the United States: Is It Appropriate? AJR Am J Roentgenol. 2019 Oct;213(4):W180-W184. doi: 10.2214/AJR.19.21386. Epub 2019 Jun 25. PMID: 31237433.

  3. Dylla L, Krothapalli N, Tu L, Payabvash S, Burke JF, Sheth KN, Wira C, de Havenon A. Trends in Head CT Use in US Emergency Department Patients From 2007 to 2022: A Nationwide Analysis. Neurology. 2025 Dec 23;105(12):e214347. doi: 10.1212/WNL.0000000000214347. Epub 2025 Nov 19. PMID: 41259742.

  4. Sierink J, Treskes K, Edwards M et al. Immediate total-body CT scanning versus conventional imaging and selective CT scanning in patients with severe trauma (REACT-2): a randomised controlled trial. The Lancet, 2016; 388, 673-683. https://doi.org/10.1016/S0140-6736(16)30932-1.

  5. Ather, S., Nash, K., Alexander, J. et al. CT scan evaluation of injuries in patients over 60 years old following a fall from standing height. Emerg Radiol 32, 765–772 (2025). https://doi-org.uc.idm.oclc.org/10.1007/s10140-025-02373-y

AUTHORSHIP

Written by: Kate Gallen, MD, PGY-4 and Erin Vaughan, MD, PGY-4 at the University of Cincinnati Department of Emergency Medicine

Writing, Editing, Posting, and Audio Editing by Anita Goel, MD; Associate Professor, APD of UC EM Residency Program, and Co-editor of Tamingthesru.com

Editing and Posting by Haley Escheman, MPH; Program Administrator at the University of Cincinnati Department of Emergency Medicine and Co-editor of Tamingthesru.com

Cite as: Gallen, K; Vaughan, E; Goel, A. To Scan or Not to Scan: Trauma Imaging in the Age of the Pan-Scan. TamingtheSRU.com. www.tamingthesru.com/blog/journal-club/trauma-imaging-to-pan-scan-or-not. 8/26/26.