RPS 1117 - Emergency radiology: new technologies and workload challenges

Author Block: B. M. Schaarschmidt¹, J. Hegmanns¹, J. Wulff¹, V. Haase², S. Faby², C. Bäumer¹, S. Zensen¹, J. Haubold¹, B. Hartung¹; ¹Essen/DE, ²Forchheim/DE
Purpose: Gunshot deaths are a worldwide health concern. Especially in patients with lodged bullets or forensic analyses, image-based bullet characterization is of major interest. Therefore, the present study investigated bullet differentiation from different materials using photon counting computed tomography (PCCT).
Methods or Background: Using a new research scan mode, six lead and three brass bullets were analyzed on a NAEOTOM Alpha PCCT system (Siemens Healthineers, Forchheim, Germany). For each scan, a set of four images was reconstructed using four different energy thresholds of the detector (20, 55, 72, and 90 keV).
Two independent readers placed three circular regions of interest (ROI) on the 20 keV threshold images on an OsiriX Workstation (Pixmeo SARL, Bernex, Switzerland). These ROIs were then automatically duplicated to the other threshold images. Dual energy indices (DEIs) were computed for the energy threshold pairs of 20/90 keV, 55/90 keV, and 72/90keV based on the measured HUmean and HUmax values.
Results or Findings: DEIs of lead and brass projectiles differed significantly, most notably for the 20/90 keV DEI HUmean (Qr40): lead: -0.085±0.021, brass: 0.024±0.048, p<0.001; HUmax (Qr40): lead: -0.093±0.011, brass: 0.023±0.057, p<0.001). For the 55/90 keV and 72/90 keV DEIs, differences between the two projectile materials decreased, but remained statistically significant.
Conclusion: In the DEIs derived from different energy threshold images obtained by PCCT, significant differences could be observed between lead and brass bullets. Therefore, PCCT might be a potential technique for bullet material analysis in both clinical and forensic imaging.
Limitations: Phantom study only.
Funding for this study: The study was performed at Siemens Healthineers facilities in Forchheim, Germany, with support from Viktor Haase and Sebastian Faby (employees of Siemens Healthineers AG).
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: As no human or animal subjects were investigated in this study, no approval by the local ethics committee was necessary.

Author Block: H-L. Kaatsch, B. V. Becker, D. Dillinger, J. Piechotka, C. Schreyer, R. Schwab, D. Overhoff, S. Waldeck; Koblenz/DE
Purpose: The aim of this study was to assess the usability of virtual monoenergetic images (VMIs) derived from photon-counting detector CT (PCD-CT) for discriminability of severe lung injury and atelectasis after thoracic trauma.
Methods or Background: We retrospectively selected 20 polytraumatized patients, who underwent contrast-enhanced whole-body PCD-CT and showed simultaneous presence of trauma-associated atelectasis and pulmonary injury. VMIs were reconstructed from 40 to 120 keV at 10 keV increments. Quantitative image analysis was performed based on density measurements and the calculation of injury-to-atelectasis contrast-to-noise ratio (CNR)). Three radiologists rated subjective discriminability, noise perception and overall image quality by means of a 5-point Likert scale.
Results or Findings: CT values for severe lung injury and atelectasis differed significantly at each keV level (p < 0.001) with a gradual decrease for atelectasis from 342 ± 97 HU at 40 keV to 69 ± 15 HU at 120 keV and a near constant behavior for severe lung injury from 42 ± 49 HU at 40 keV to 44 ± 22 at 120 keV. In line with this, the highest injury-to-atelectasis CNR was achieved at 40 keV (3.97) with a continuous decline down to 120 keV (1.21). CNR reached no significant differences between 40 and 50 keV as well as 110 and 120 keV (p >0.05), whereas all other pairings were significantly different (p<0.05). The best ratings for subjective discriminability were reported for VMIs at 40 keV, whereas VMIs at 60-70 keV provided the optimal noise perception and overall image quality.
Conclusion: Low-keV VMIs at 40-50 keV from PCD-CT considerably improved the discriminability of severe lung injury and atelectasis after thoracic trauma.
Limitations: Lack of a validated reference standard for lung injury vs. atelectasis, retrospective study design and small sample size.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study is a retrospective single-centre analysis that has been approved by the local ethics committee of the chamber of physicians Rhineland-Palatinate in Mainz, Germany (number 2022-16314).

Author Block: H-J. Meyer, T. Dermendzhiev, T. Denecke, M. Struck; Leipzig/DE
Purpose: Body composition parameters provide relevant prognostic significance in critical care cohorts and cancer populations. Published results regarding polytrauma patients are inconclusive to date. The goal of this study was to analyse the role of body composition parameters in severely injured trauma patients.
Methods or Background: All consecutive patients requiring emergency tracheal intubation and mechanical ventilation before initial computed tomography (CT) at a level-1 trauma centre over a 12-year period (2008-2019) were reanalysed. The analysis included CT-derived body composition parameters based upon whole-body trauma CT as prognostic variables for 30-day mortality, intensive care unit length of stay (ICU LOS) and mechanical ventilation duration.
Results or Findings: Four hundred seventy-two patients (75% male) with a median age of 49 years, median injury severity score of 26 and 30-day mortality rate of 22% (104 patients) met the inclusion criteria and were analysed. Regarding body composition parameters, 231 patients (49%) had visceral obesity, 75 patients had sarcopenia (16%) and 35 patients had sarcopenic obesity (7.4%). After adjustment for statistically significant univariable predictors age, body mass index, sarcopenic obesity, visceral obesity, American Society of Anesthesiologists classification ≥3, injury severity score and Glasgow Coma Scale ≤ 8 points, the Cox proportional hazard model identified sarcopenia as significant prognostic factor of 30-day mortality (hazard ratio 2.84; 95% confidence interval 1.38-5.85; P = 0.004), which was confirmed in Kaplan-Meier survival analysis (log-rank P = 0.006).
Conclusion: In a multivariable analysis of mechanically ventilated trauma patients, CT-defined sarcopenia was significantly associated with 30-day mortality whereas no associations of body composition parameters with ICU LOS and duration of mechanical ventilation were observed.
Limitations: It is a single-center study with a retrospective design.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approval by the ethics committee at the Medical Faculty, Leipzig University, Leipzig, Germany (IRB00001750, project ID 441/15ek, September 14, 2020)

Author Block: A. S. Brendlin, U. Schmid, S. Afat; Tübingen/DE
Purpose: To identify the optimal low-dose CT protocol that minimizes radiation exposure while preserving high image quality and diagnostic accuracy in patients presenting with acute abdomen.
Methods or Background: A prospective, randomized study was conducted with 180 patients assigned to one of three CT protocols. Each protocol included high-dose (HD) and low-dose (LD) scans reconstructed using Iterative Reconstruction (IR2) and AI Denoising (AID). Subjective image quality was assessed by radiologists evaluating diagnostic confidence, contrast, and sharpness. Objective image quality metrics, including noise and contrast-to-noise ratio (CNR), were measured. Diagnostic accuracy was evaluated through sensitivity and specificity calculations for detecting abdominal pathologies.
Results or Findings: Protocol 2 LD achieved the lowest Size-Specific Dose Estimate (SSDE) at 4.83 mGy, significantly reducing radiation dose compared to Protocols 1 and 3 (P < 0.001). AID significantly enhanced subjective image quality in LD scans across all protocols, with Protocols 2 and 3 achieving ratings comparable to HD scans with IR2. Objective assessments showed that AID substantially reduced image noise and increased CNR in LD scans, with Protocol 2 LD exhibiting the highest CNR. In outcome analysis, both Protocols 1 and 2 demonstrated 100% sensitivity and specificity in LD scans with AID, eliminating false negatives and matching the diagnostic performance of HD scans. Protocol 3 maintained high diagnostic accuracy across all doses and reconstruction methods.
Conclusion: Protocol 2 with AID emerges as the most effective low-dose CT strategy, offering significant radiation dose reduction while maintaining superior image quality and diagnostic accuracy.
Limitations: - Single-Center Study with Limited Sample Size
- Potential Observer Bias in Subjective Assessments
- Lack of Long-Term Outcome Data
- Equipment and Protocol Specificity
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: University Hospital Tuebingen

Author Block: J. Xie¹, T. Wang², G. Zhang², J. Huang¹, M. Wang¹, Y. Lin¹; ¹Taizhou/CN, ²Shanghai/CN
Purpose: To investigate the feasibility and realiability of replacing routine cerebral CT angiography (CTA) with CT perfusion (CTP)-derived cerebral CTA by using artificial intelligence iterative reconstruction (AIIR) for acute ischemic stroke (AIS) patients.
Methods or Background: Forty-nine patients (33-93 y, male: 35) with AIS undergoing a cerebral CTP and a routine CTA were prospectively collected. CTA images derived from CTP at the arterial phase (100kVp/150mAs) were reconstructed with hybrid iterative (Group A1) and AIIR (Group A2), whereas routine CTA images (100kVp/ref. 200mAs) were obtained with hybrid iterative reconstruction (Group B). Two radiologists independently located the responsible vessels, with digital subtraction angiography (DSA) as reference standard. They further graded the image noise, sharpness of the vascular edge, small vessel visibility, and overall diagnosability using a five-point Likert scale (1: poor, 5: excellent). Objective parameters, including the SNR and CNR of the internal carotid artery, the middle cerebral artery, and the basilar artery, were also calculated.
Results or Findings: The diagnosis of responsible vessels was consistent by both radiologists, where the diagnostic accuracy of Groups A2 and B were comparable (47/49, 95.92%) and higher than that in Group A1 (43/49, 87.76%). The inter-observer agreement was excellent (κ = 0.84).All subjective scores were significantly higher in Group A2 than those in Groups A1 and B (all p < 0.017), especially for the small vessel visibility (4.9 ± 0.2 vs.2.8± 0.4 vs. 4.2 ± 0.5). AIIR significantly reduced noise, leading to a significantly higher SNR and CNR for all arteries in Group A2 than those in Groups A1 and B (all p < 0.017).
Conclusion: Perfusion-derived cerebral CTA by use of the AIIR achieves comparable diagnostic image quality to that of the routine cerebral CTA for AIS patients.
Limitations: Not applicable
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Not applicable

Author Block: L. Mabit, G. Herpe; Poitiers/FR
Purpose: Investigate the real-world performance of qER.AI, an artificial intelligence-based CT haemorrhage detection tool, in a post-traumatic population.
Methods or Background: Retrospective monocentric observationnal study of a dataset of consecutively acquired head CT scans at the emergency radiology unit to explore a brain trauma. AI performance was compared to groundtruth determined by expert consensus. A subset of nighshift cases with radiological report of junior resident was compared to AI results and groundtruth.
Results or Findings: 682 head CT scan were analyzed. AI demonstrated a sensitivity of 88.8% and specificity of 92.1% overall, with a positive predictive value of 65.4% and a negative predictive value of 98%. AI's performance was comparable to junior residents in detecting ICH, with the latter showing a sensitivity of 85.7% and a high specificity of 99.3%. Interestingly, the AI detected two out of three ICH cases missed by junior residents. When AI and residents performances were combined, the sensitivity improved to 95.2%, and the overall accuracy reached 98.8%.
Conclusion: This study shows a better performance of AI and radiologist resident associated than each one alone. These results are encouraging to rethink the radiological workflow and the future of triage of this large population of brain traumatised patients in emergency unit.
Limitations: The limitations of the study are exclusion of some CTs due to logistics issues (potential selection bias), and a low number of positive ICH cases in the nightshift subset.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was reviewed and approved by the Institutional Review Board of CERIM (CRM-2401-400).

Author Block: M. T. Meyer, E. M. Merkle, T. Heye; Basel/CH
Purpose: This study aims to identify trends explaining the significant rise in CT examinations ordered by the emergency department (ED) of a tertiary hospital in the last decade (2014 to 2023) using large language models (LLM).
Methods or Background: Radiology Information System data were extracted for CT scans performed on ED patients between 2014-2023. The open-source Llama 3.1 405B LLM was used to classify each report into YES (expected pathology confirmed), NO (no relevant pathology), and OTHER (unexpected but relevant pathology found). Trends were analyzed by body-region, focusing on patients older than 65 years, as this group showed the highest increase in imaging.
Results or Findings: Over the past decade, the number of CT scans increased 2.2 times for ED patients, with a more pronounced rise for patients over 65 years (2.4). Preliminary results show that the LLM achieved an accuracy of 84% compared to a manual review of 500 randomly sampled reports. Scans of abdomen/pelvis (YES in 49-60%) and thorax/abdomen/pelvis (YES in 54-63%) remained stable with minor annual fluctuation. CT scans of the skull in polytrauma patients showed steady increase in NO findings from 43% (2016) to 59% (2022). CT of the skull showed a gradual increase in NO findings from 57% (2015) to 66% (2022). CT of the thorax remained relatively stable (YES 41-46% from 2014-2019), with notable peaks during the COVID-pandemic (52% in 2021).
Conclusion: Diagnostic yield across different organ groups varies greatly with high proportions of NO findings in skull CTs (typically to rule-out bleeding). Over time, unremarkable CT scans, particularly of the skull, have increased, while trends for other body regions (e.g., thorax/abdomen/pelvis), were less distinct.
Limitations: The results are preliminary. Accuracy of the LLM is limited, which might lead to over-/underestimation of trends.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: The study is retrospective and General Consent is available.

Author Block: P. Rohan, H. Briody, C. Mccarthy, M. M. Morrin; Dublin/IE
Purpose: The demand for acute diagnostic radiology services during on-call hours continues to increase, placing strain on radiology trainees. This study aims to assess the on-call workload for Radiology Specialist Registrars (SpRs) over a five-year period at a model 4 tertiary referral centre in Ireland.
Methods or Background: A retrospective review was conducted, analysing the volume of computed tomography (CT) scans performed during on-call hours (weekdays 17:00-08:00, weekends, and public holidays) across three months—January, July, and November—from 2019 to 2023. Data were categorized by study type, focusing on Emergency Department (ED) requests and key scan types, including non-contrast brain CT (NCB), CT abdomen/pelvis (CTAP), CT thorax/abdomen/pelvis (CT TAP), and cerebral stroke protocol ("FAST"). Statistical analysis included percentage changes and paired t-tests.
Results or Findings: Between 2019 and 2023, there was a 25% increase in the total number of on-call CTs performed (p = 0.098), with a significant 46% rise in ED-related studies (p < 0.05). Significant increases were observed in NCBs (38%, p < 0.05) and CT TAPs (220%, p < 0.05). The number of CTs performed after midnight increased by 82% (p = 0.055), while FAST protocol CTs rose by 41% (p = 0.056), reflecting the growing incidence of stroke in Ireland.
Conclusion: The increasing on-call workload for Radiology SpRs, particularly driven by ED requests and the rising demand for stroke imaging, underscores the need for careful planning and resource allocation to manage future demand. Addressing trainee workflows is essential to sustaining radiology services while maintaining high standards of care.
Limitations: This retrospective study is limited to on-call CT workload. Other modalities like ultrasound, MRI, and X-rays, as well as communication burdens with clinical teams, were not assessed and should be explored in future studies.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Ethics committee approval not required.

Author Block: F. Kempter, D. Jäschke, J. Vosshenrich, B. Ceresa, T. Heye; Basel/CH
Purpose: To investigate the impact of COVID-19 pandemic-related measures on trends and volume in CT examinations requested in the emergency department.
Methods or Background: CT examinations of the head, chest, and/or abdomen-pelvis (n=161,008), and chest radiographs (n=113,240) performed at our tertiary care hospital between 01/2014- 12/2023 were retrospectively analyzed. CT examinations (head, chest, abdomen, dual- region and polytrauma) and chest radiographs requested by the emergency department during (03/2020-03/2022) and after the COVID-19 pandemic (04/2022- 12/2023) were compared to a pre-pandemic control period (02/2018-02/2020). Analyses included CT examinations per emergency department visit, and prediction models based on pre-pandemic trends and inpatient data. A regular expressions text search algorithm determined the most common clinical questions.
Results or Findings: The usage of dual-region and chest CT examinations were higher during (+116,4% and +115.8%, respectively; p<0.001) and after the COVID-19 pandemic (+88,4% and +70.7%, respectively; p<0.001), compared to the control period. Chest radiograph usage decreased (-54.1% and -36.4%, respectively; p<0.001). The post-pandemic overall CT examination rate per emergency department visit increased by 4.7%. The prediction model underestimated (p<0.001) the growth (dual-region CT: 22.3%, chest CT: 26.7%, chest radiographs: -30.4%), and the rise (p<0.001) was higher compared to inpatient data (dual-region CT: 54.8%, chest CT: 52.0%, CR: -32.3%). Post- pandemic, the number of clinical questions to rule out “pulmonary infiltrates”, “abdominal pain” and “infection focus” increased up to 235.7% compared to the control period.
Conclusion: Following the COVID-19 pandemic, chest CT and dual-region CT usage in the emergency department experienced a disproportionate and sustained surge compared to pre-pandemic growth.
Limitations: Single-center, retrospective design limits generalizability. CT as standard imaging for suspected COVID-19 pneumonia (2020–2022) may explain the shift. Only clinical questions, not diagnoses, were analyzed. Despite a large sample size, data mislabeling is possible.
Funding for this study: Not applicable.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The local ethics committee of northwestern and central Switzerland (EKNZ, project ID 2022-01016) approved this study.

Author Block: A. Gmati, Z. Foster, M. Mobley; Warwick/UK
Purpose: Radiology has transformed how acute medicine is practiced, with growing imaging demands placing significant strain on radiology departments in the UK. This study retrospectively examines 18 years of urgent inpatient and emergency CT reporting at South Warwickshire University NHS Foundation Trust (SWFT) to assess trends in workload, staffing, and operational changes over this period.
Methods or Background: Data were extracted from the Radiology Information System (RIS) at SWFT, encompassing approximately 140,000 urgent scans performed since 2007. These were analysed to show changes over time such as seasonal variability and peaks in workload throughout the week, as well as the overall trend for increased imaging.
Results or Findings: Urgent CT workload at SWFT has significantly increased over the study period, reflecting national trends. This timescale covers a period of rapid growth and operational change at SWFT, such as the introduction of weekend shifts and the implementation of outsourced teleradiology for out-of-hours reporting. Typical daily reporting numbers have increased from 12 scans per day in 2007 to over 50 in 2024. Staffing has not kept pace, with WTE consultant numbers dropping from 12 in 2019 to 9.5 in 2023. Despite outsourcing, many departments continue to struggle with growing diagnostic demands.
Conclusion: Across the UK, CT usage surged from 1 million scans in 1997 to over 6.7 million in 2021. Rising CT demand at SWFT reflects broader national trends, with increasing pressure on radiology services. The UK’s Royal College of Radiologists predicts a shortage of 1,669 radiologists by 2025, highlighting a national critical staffing issue. Operational changes such as weekend working may provide temporary relief but place increasing demands on the same pool of radiologists. Systemic reforms and increased investment are essential to meet future diagnostic demands.
Limitations: N/A
Funding for this study: N/A
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: N/A

Author Block: J. Sarnecki, M. T. Meyer, E. M. Merkle, T. Heye; Basel/CH
Purpose: To investigate the trends in imaging in emergency patients over the last decade.
Methods or Background: 190'028 emergency CT examinations from 1/1/2015 to 31/12/2023 of patients aged 18-100 years, performed within 24h of the request, were included. The examination time was stratified into dayshift (8-17:30h), late-shift (17:30-22h), night-shift (22-8h) and weekend-dayshift (Saturday/Sunday 8-17:30h). The patients were divided into two age groups (18-64 versus 65-100 yrs.) and binned using 5-year increments. The percentage increase in imaging numbers was calculated based on 2015.
Results or Findings: A sharp overall increase in CT imaging numbers was observed in 2020 (18-64 yrs.: 127.0% vs. 65-100 yrs.: 155.3%), peaking in 2022 (18-64 yrs.: 182.4% vs. 65-100 yrs.: 235.6%). The mean age in the 18-64 yrs. group increased from 44.8 (2015) to maximally 46.3 (2022), but did not increase for 65-100 yrs. (79.2 vs. 79.3 yrs.).
The day-shift imaging numbers showed a linear steady increase, whereas the night-shift examinations showed the strongest increase, peaking in 2023 with 267.5% (18-64 yrs) and 403.0% (65-100 yrs) followed by changes in weekend and late-shift CT numbers (18-64 yrs.: 119.8%;127.1% vs. 65-100 yrs.: 173.1%; 139.0%).
Between 2020-2023 for the younger age group, age-bins 55-59 (199.5-260.9%) and 60-64 (140.8-200.6%) showed the largest relative increase compared to 2015 for late-, night- and weekend-dayshift CTs combined (all age bins 18-64yrs: 30-112.2%). In the 65-100 yrs. group, the largest relative increase was seen for patients 95-100 years old (318.2-360.0%) compared to other 5-year age bins (145.7-276.8%).
Chest, Chest-Abdomen-Pelvis and Polytrauma CT showed the greatest increase.
Conclusion: The results support that a change in imaging was triggered and sustained by the COVID-19 pandemic with a disproportionate increase in CT imaging volume overall and especially for older patients during non-day-shifts.
Limitations: Retrospective, single-center study.
Funding for this study: No funding.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Not applicable

Author Block: A. Martínez López, G. Pagán Vicente, E. Otón González, H. Ortiz Mayoral, E. C. Cotillo Ramos, M. S. Canales, B. Molina-Lozano, J. Plasencia Martínez, I. Santiago Suárez; Murcia/ES
Purpose: The number of non-traumatic urgent cranial computed tomography (NT-UCCT) is exponentially increasing but limited research has been conducted on the quality of clinical justification. We aimed (1) to assess how clinical information in the electronic NT-UCCT request agreed with that provided in the emergency department discharge summary and (2) to analyze the potential effect of those discrepancies on the NT-UCCT overload.
Methods or Background: Patients undergoing NT-UCCT in 2017-2021 were randomly selected for this retrospective study. Signs and symptoms (S/S) in electronic request and emergency department discharge summary, acute and relevant computed tomography (CT) findings, and final diagnosis at emergency department discharge summary were collected. Concordance between both and their association with CT findings and final diagnosis were analyzed.
Results or Findings: We recruited 156 patients: 80 men; mean age, 55. Acute, relevant CT findings were detected in 28 cases (17.9%). The final diagnosis was neurological disease 46 (29.5%), non-neurological disease 58 (37.2%), and no definitive diagnosis 51 (32.7%). Full agreement between the electronic request and emergency department discharge summary occurred in 36 patients (23.1%). Motor deficit was the most frequent false positive S/S (18; 11.54%), having low positive predictive value (30.30%; 95%CI 15.59-48.71%) and worst association with acute relevant CT findings than when true positive (OR 2.54; 95%CI 0.04-6.21 vs. OR 6.26, 95%CI 2.21-17.78). Nausea/vomiting was the third most common false negative S/S (13; 10.26%) and reduced the likelihood of acute relevant CT findings (OR 0.126; 95%CI 0.016-0.971; p = 0.020).
Conclusion: Discrepancies between electronic request and emergency department discharge summary were observed in >75% of patients, leading to unnecessary NT-UCCT tests.
Limitations: Differences in how clinical information is recorded, the variability among physicians, results not applicable to large hospitals, small sample size limited detailed analysis.
Funding for this study: No
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the ethics committee.