Research Presentation Session: Emergency Imaging

RPS 917 - Optimising imaging in emergency radiology: current and future trends

February 29, 12:30 - 13:30 CET

7 min
An evaluation of multiple upper limb x-rays: is adjacent imaging necessary?
Dania Abu Awwad, Camperdown / Australia
Author Block: D. Abu Awwad, E. U. Ekpo; Sydney, NSW/AU
Purpose: Medical imaging is a valuable diagnostic tool in emergency departments. However, the reliance on imaging leads to increased practices that may deviate from evidence-based guidelines. X-ray requests for extremities sometimes also simultaneously ask for X-ray projections for other adjacent regions. However, the usefulness of these additional projections is unclear. Our aim was to assess the diagnostic yield of X-rays performed on upper limb regions adjacent to the area of injury.
Methods or Background: Data were collected retrospectively and included all patients who had X-rays of multiple upper limb regions. Clinical history notes and radiological reports were used to establish the diagnostic yield of X-rays performed on a region adjacent to the injured limb, and the association between patient symptoms and diagnostic outcomes were assessed using Chi-Square analysis.
Results or Findings: A total of 1455 upper limb X-ray imaging were performed on 591 patients. A third of these patients had three or more X-rays. About 95% of the abnormalities were detected on X-rays performed at the site of injury. The diagnostic yield of X-rays performed on the region adjacent to the injured limb was only 1.5%. Chi-Square analysis showed that X-ray examination of adjacent limb was less likely to detect new (previously undetected) abnormalities (χ2(2) = 498.981; p = <0.001). New abnormalities were more common in the wrist or shoulder, and the majority were due to an injury and in women older than 65 years.
Conclusion: Adjacent upper limb images have very low diagnostic yield or impact. A change in the practice is needed to maximise the benefits of imaging and reduce the cost and risks associated with additional X-ray imaging of asymptomatic adjacent limbs.
Limitations: No limitations were identified.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the Sydney Local Health District Human Research Ethics Committee (2022/ETH01291).
7 min
High-pitch head CT in uncooperative emergency department patients with acute head trauma: evaluation of image quality and detection of acute intracranial pathologies
Jan-Erik Scholtz, Frankfurt a. Main / Germany
Author Block: J-E. Scholtz, D. Leitner, L. D. Grünewald, S. Mahmoudi, V. Koch, C. Booz, T. Vogl; Frankfurt a. Main/DE
Purpose: The purpose of this study was to evaluate image quality and diagnostic accuracy of an unenhanced high-pitch head CT protocol used in uncooperative emergency department (ED) patients after acute trauma.
Methods or Background: We retrospectively compared high-pitch (1.55) head CT protocol (CTDIVOL 34.4 mGy) used in uncooperative ED patients and 1:1 age-matched ED patients who underwent standard-pitch (0.55) head CT protocol (CTDIVOL 39.5 mGy) after acute trauma between January 2023 and August 2023. Gray matter (GM) signal-to-noise ratio (SNR), white matter (WM) SNR, GM-WM contrast-to-noise ratio (CNR), and posterior fossa artefact index (PFAI) were compared. Two radiologists performed qualitative image evaluation of intracranial and bone structures, artefacts, and diagnostic evaluation for acute intracranial pathologies and fractures.
Results or Findings: Overall, 87 patients [male, n=55(63.2%), 68±22 years] underwent high-pitch CT protocol. Quantitative image evaluation did not show significant differences between high-pitch and standard protocols: GM SNR, mean±SD, 18.3±3.4 vs. 17.6±2.6, WM SNR, 15.2±2.5 vs. 14.8±2.3, GM-WM CNR 2.3±0.7 vs 2.2±0.6, PFAI, 3.4±0.3, all p≥0.41. Grey-white differentiation [median (IQR); 5(4,5) vs. 5(4,5)], delineation of cerebrospinal fluid spaces, and bone structures were rated very good for both protocols without significant differences (p≥0.05). Artefacts in the supratentorial region were low in both protocols (p=0.09), while beam-hardening artefacts in the infratentorial region were slightly worse in high-pitch scans (p=0.001). Diagnostic confidence to evaluate for intracranial haemorrhage, brain herniation, and fracture was very good for both protocols without significant differences. Inter-rater agreement for the detection of intracranial haemorrhages (n=40), herniation (n=17), and fractures (n=14) was excellent for both protocols (ĸ,1.0).
Conclusion: High-pitch head CT protocol is a safe and robust alternative in uncooperative ED patients to evaluate for acute intracranial pathologies after trauma.
Limitations: The high-pitch head protocol has not been evaluated for ischaemic stroke imaging.
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 was a retrospective study with a waiver for informed consent.
7 min
A simple clinical algorithm for prediction of relevant CT findings could reduce the number of low-value cranial CT scans by more than 20%
Marta Sánchez Canales, Murcia / Spain
Author Block: J. M. Plasencia Martinez, M. S. Canales, E. Otón González, N. I. Casado Alarcón, E. C. Cotillo Ramos, H. Ortiz Mayoral, B. Molina-Lozano, J. M. Garcia Santos; Murcia/ES
Purpose: The number of cranial CT scans is exponentially increasing, without a clear benefit. Our aim is to determine the yield of urgent cranial CT depending on the clinical reason for consultation (RC), and to put forward a diagnostic algorithm.
Methods or Background: This was a retrospective, randomised study in patients who underwent urgent cranial CT for non-traumatic reasons, between 2017 and 2021. Using binary logistic regression, the discriminatory capacity of the variables was analysed. The independent variables were RC and personal history, and the dependent variables are relevant radiological findings (RRF) described in urgent cranial CT: acute ischaemia and haemorrhage, mass, oedema, or unknown hydrocephalus, and relevant clinical-radiological findings (RCRF): patients with RRF and/or need for hospital admission.
Results or Findings: We recruited 702 patients, median age 62 [interquartile range 47-76] years, 339 (48.3%) males.
Variables that increased the RCRF risk (Odds Radio -OR- >1, P<0.05) were motor deficit (OR_5.086; 95%CI_2.893-8.940), speech deficit (OR_5.042; 95%CI_2.871-8.854), seizure disorder (OR_4.688; 95%CI_2.106-10.436), cognitive impairment (OR_2.639; 95%CI_1.316-3.851), sensory deficit (OR_2.223, 95%CI_1.300-3.800), oncological history (OR_1.750; 95%CI_1.238- 2.475), and sudden altered mental status (OR_1.553; 95%CI_1.055-2.286). Variables that decreased the RCRF risk (OR<1, P<0.05) were dizziness (OR_0.652; 95%CI 0.45-0.943), nausea-vomiting (OR_0.594; 95%CI_0.385-0.917), syncope-presyncope (OR_0.580; 95%CI_0.357-0.941), acute headache (OR_0.528; 95%CI_0.368-0.756), and vertigo (OR_0.267; 95%CI_0.142-0.505). When the above RCs did not show discriminative ability, the ability of the remaining RCs was re-evaluated. An algorithm depicted is segregated, with sensitivity and negative predictive value above 92%, which would reduce 23.9% of CTs in the full sample and 35.2% in non-admitted patients, failing to diagnose 7% of RRF.
Conclusion: A clinical algorithm is proposed for relevant radiological findings in non-traumatic urgent cranial CT scans, potentially avoiding at least 23% of CT scans.
Limitations: The study is awaiting prospective external validation.
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 approved with code CETI: 02/22.
7 min
Evaluation of low-dose whole brain CT perfusion-driven CT angiography utilising a deep learning image reconstruction algorithm
Yuhan Zhou, Zhengzhou / China
Author Block: Y. Zhou, L. Lei, Z. Wang, W. Cao, S. W. Yue; Zheng Zhou/CN
Purpose: The purpose of this study is to investigate the image quality and diagnostic accuracy of low-dose whole brain CT perfusion-driven CT angiography with deep learning image reconstruction (DLIR) in patients with patients with acute ischeamic stroke (AIS) caused by large vessel occlusion (LVO).
Methods or Background: This prospective study collected 62 patients with AIS caused by LVO, divided into standard-dose (80keV 150Ams) and low-dose (80keV 100Ams) CTP examination. The FBP, ASIR-V40% / 80% were using standard-dose group, and ASIR-V80% and DLIR (M, H) were using low-dose group. ROIs were drawn in the CTP arterial phase images of siphon portion of the internal carotid artery (ICA), middle cerebral artery M1 segment (MCA-M1), and temporal lobe for objective evaluation of image noise, SNR, and CNR. Subjective evaluation included edge sharpness of vascular lumen, display of small blood vessels, and overall image quality.
Results or Findings: The low-dose DLIR-H group showed lower image noise. CNR of low-dose DLIR-H group in the ICA and MCA-M1 were higher than standard-dose FBP, ASIR-V40% groups, and low-dose DLIR-M group (P<0.05). In subjective evaluation, the low-dose DLIR-H group was superior to the standard-dose FBP, ASIR-V40% groups, and low-dose DLIR-M group (P<0.05). The radiation dose in the low-dose group was significantly lower than that in the standard dose group (P<0.05).
Conclusion: Reconstruction of low-dose CTP arterial phase images through DLIR may aid in the detection of small responsible vessels. It provides a valuable low-dose scanning option for clinical evaluation without the need for additional scanning protocols and extra radiation exposure and shortens the examination time.
Limitations: The number of AIS patients included in our study was limited and more cases are expected for further studies.
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: Our retrospective study has obtained approval from the Institutional Review Board.
7 min
Evaluation of an optimised CT protocol for the assessment of suspected cauda equina syndrome and nerve root compression
Philip Jude Dempsey, Dublin / Ireland
Author Block: P. J. Dempsey, G. Lambe, D. T. Ryan, J. W. Power, A. Yates, G. Kenny, P. J. Macmahon; Dublin/IE
Purpose: The evaluation of suspected cauda equina syndrome and nerve root compression relies on urgent MRI. However, access to MRI can be limited in many healthcare systems, especially in the out-of-hours setting. CT, by comparison, is more readily accessible. The purpose of this study was to evaluate the diagnostic accuracy of an optimised CT lumbar spine protocol in the assessment of suspected cord and nerve root compression using MRI as the reference standard.
Methods or Background: Individuals presenting to the emergency department and referred for MRI for suspected nerve root compression were prospectively enrolled to have a CT spinal stenosis protocol in addition to MRI. Central canal and neural foraminal stenosis was qualitatively and quantitatively assessed at each lumbar level on CT by an expert radiologist blinded to the clinical information and outcome. Following a 4 week interval the process was repeated for each MRI.
Results or Findings: 59 individuals were included in the final analysis. In 22 (39%) cases no significant stenosis was identified. In a further 22 (37%) cases disc pathology was identified that was managed conservatively. 13 (22%) individuals proceeded to urgent surgical decompression. In one (2%) instance an alternative diagnosis was identified. The sensitivity, specificity, positive and negative predictive values for CT in detecting acute neural compression were 97% (CI: 82-99%), 97% (CI: 83-99%), 97% (CI: 92-99%) and 97% (CI 83- 99%) respectively.
Conclusion: CT accurately detected nerve compression and emergent surgical lesions. This can be a useful tool in selecting appropriate patients for emergent MRI in the on-call setting to allow for better emergency resource allocation.
Limitations: The study was limited by its relatively small sample size, its reliance on external multicentre validation, and from the lack of a universally agreed stenosis assessment method. This was a single centre study.
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 approved by an ethics committee.
7 min
Relevance of computed tomography for the detection of septic foci: a systematic review and meta-analysis
Ann-Christine Stahl, Berlin / Germany
Author Block: A-C. Stahl, K. Rubarth, M-I. Opper Hernando, G. Muench, M. Dewey, J. Pohlan; Berlin/DE
Purpose: This systematic review and meta-analysis was conducted to investigate the diagnostic accuracy of computed tomography (CT) in patients with suspected or confirmed sepsis.
Methods or Background: We searched Medline by using PubMed and Embase by using Ovid with a systematic search strategy to identify studies assessing the role of CT in patients with suspected sepsis or sepsis of unknown origin. Reviews, meta-analyses, editorials, comments, or case reports were not eligible for inclusion. In addition, we searched the references of the included studies to ensure no relevant studies were missed. PubMed was last searched on 01.01.2023 and Ovid on 22.01.2023. We extracted the sensitivity and specificity using 2-by-2 tables from each study. The methodological quality was assessed with the help of the QUADAS-2 tool. Pooled estimates of per-CT sensitivity, specificity, and diagnostic odds ratio were calculated by using random effects meta-analysis for proportions via logit transformation and presented as forest plots. This review was registered in PROSPERO (ID: CRD42023412009).
Results or Findings: Five studies which included an overall of 838 patients met our inclusion criteria. The different reference standards used were the final diagnosis from the discharge note, operation, local drainage, needle aspiration, and autopsy. The pooled estimate of sensitivity was 83.2% (95% CI: 69.5–91.4%) while the pooled estimate of specificity was 62.4% (95% CI: 49.9-73.5%). The pooled estimate of the diagnostic odds ratio was 9.0 (95% CI: 2.2-36.3). Both sensitivity (I2=67%, p=0.02) and odds ratio (I2=77%, p<0.01) showed significant variation between the studies.
Conclusion: CT has good sensitivity but limited specificity in patients with suspected or confirmed sepsis and may thus be considered an appropriate test.
Limitations: Due to the low number of included studies as well as their heterogeneity the generalizability of our results may be limited.
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: As the presented study is a systematic review and meta-analysis no approval by an ethics committee is needed.
7 min
The problem-solving role of the 'wait and repeat CT' approach in the diagnosis and treatment of acute abdomen
Esra Akçiçek, Ankara / Turkey
Author Block: E. Akçiçek, A. G. Erdemir, I. S. Idilman, M. R. Onur, E. Akpinar; Ankara/TR
Purpose: Computed tomography (CT) findings in patients with acute abdominal symptoms are sometimes insufficient to make a definitive diagnosis. Patients may be offered repeat imaging and, to our knowledge, the results of this approach have not been studied. We aimed to investigate the impact of the 'wait and repeat CT' approach on the diagnostic and therapeutic processes of emergency patients with acute abdominal symptoms who could not be diagnosed with the initial CT but were diagnosed with a repeat CT.
Methods or Background: Approval was obtained from the ethics committee. Patients admitted to the emergency department between January 2013 and July 2023 (≥18 years) were selected from those who had a repeat CT examination on the same admission. Trauma patients and initial examinations with artefacts were excluded. According to the findings of repeat CT, patients were divided into five subgroups: preliminary diagnosis did not change (group-A), suspicious preliminary diagnosis confirmed (group-B), progression after initial diagnosis (group-C), regression after initial diagnosis (group-D), and completely different diagnosis (group-E). The diagnoses in each group and the relationships between the groups were analysed statistically.
Results or Findings: 228 examinations were found, of which 72 were excluded due to artefacts and seven due to trauma. Of the 149 patients, 21 were in group-A (14.09%), 60 in group-B (40.26%), 32 in group-C (21.47%), 25 in group-D (16.77%), and 11 in group-D (7.38%). Overall, the most frequent cases were partial bowel obstruction (n: 41, 27.51%) and the majority of patients whose findings regressed to the second CT (group-D; n:18, 72.0%). The "wait and repeat" approach is statistically significant in the follow-up and discharge decision of patients with partial obstruction (p<0.01).
Conclusion: The 'wait and repeat' approach may be helpful in follow-up of acute abdomen, especially if it is a bowel obstruction.
Limitations: The number of patients was limited.
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 approved by the Hacettepe University Ankara, Ethics commitee No: GO 23/566.
7 min
The distribution of computed tomography findings for nonagenarians with acute abdominal conditions: a descriptive study for more than a decade of observation
Ayse Nur Bolukcu, Ankara / Turkey
Author Block: A. G. Erdemir, A. N. Bolukcu, E. Akçiçek, M. R. Onur, I. S. Idilman, E. Akpinar; Ankara/TR
Purpose: The objective of the study was to apply computed tomography (CT), which is useful to determine the causes of acute abdomen in nonagenarian (≥90 years) individuals, since they are less likely to present with the traditional symptoms. We aimed to describe the CT scan findings of acute abdominal etiologies in nonagenarian patients over a ten-year period, which to our knowledge has never been studied in this context.
Methods or Background: Nonagenarians with acute abdomen admitted to the emergency department between January 2013 and June 2023 with CT (n:620) were studied. Of these, trauma patients (n:112) were excluded. For the remaining 508 patients, an assessment was made based on symptoms, demographics, etiology, surgical interventions, and mortality within the following day, week, and month.
Results or Findings: Positive findings for acute abdomen were detected in 258 patients (50.78%). There were 131 patients (50.77%) requiring surgical intervention and 54 of them (20.93%) were able to undergo surgical intervention. According to primary acute abdominal pathology, they were categorized as follows: bowel obstruction (n:36, 13.95%), acute cholecystitis (n:29, 11.24%), arterial occlusion (n:28, 10.85%), stercoral colitis (n:21, 8.13%), bowel infection (n:16, 6.20%), kidney stone (n:15, 5.81%), bowel perforation (n:8, 3.10%), venous occlusion (n:6, 2.32%), acute appendicitis (n:4, 1.55%). We categorised patients based on their mortality within the following day (22.72%), week (34.09%), and month (43.18%). Malignancy (n:114, 22.48%) was the most frequent chronic abdominal pathology accompanying them.
Conclusion: The spectrum of acute abdominal etiology in nonagenarians, studied for the first time on such a large scale, differs considerably from other segments of the population. Most importantly, admission to CT for acute abdomen in nonagenarians can be an indicator of the likelihood that more than a third (or even nearly half) may die within a month.
Limitations: It was a single-centered and retrospective study.
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 approved by Hacettepe University Noninterventional Clinical Research Ethics Committee.

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