Increasing use of CT requested by emergency department physicians in tertiary hospitals in Western Australia 2003-2015: an analysis of linked administrative data

Demonstrating the use of population level data to investigate trends in the rate, radiation dose and cost of Computed Tomography across clinical groups: Are there any areas of concern?

INTRODUCTION

Increases in computed tomography (CT) use may not always reflect clinical need or improve outcomes. This study aimed to demonstrate how population level data can be used to identify variations in care between patient groups, by analysing system-level changes in CT use around the diagnosis of new conditions.

METHODS

Retrospective repeated cross-sectional observational study using West Australian linked administrative records, including 504,723 adults diagnosed with different conditions in 2006, 2012 and 2015. For 90 days pre/post diagnosis, CT use (any and 2+ scans), effective dose (mSv), lifetime attributable risk (LAR) of cancer incidence and mortality from CT, and costs were assessed.

RESULTS

CT use increased from 209.4 per 1000 new diagnoses in 2006 to 258.0 in 2015; increases were observed for all conditions except neoplasms. Healthcare system costs increased for all conditions but neoplasms and mental disorders. Effective dose increased substantially for respiratory (+2.5 mSv, +23.1%, P < 0.001) and circulatory conditions (+2.1 mSv, +15.4%, P < 0.001). The LAR of cancer incidence and mortality from CT increased for endocrine (incidence +23.4%, mortality +18.0%) and respiratory disorders (+21.7%, +23.3%). Mortality LAR increased for circulatory (+12.1%) and nervous system (+11.0%) disorders. The LAR of cancer incidence and mortality reduced for musculoskeletal system disorders, despite an increase in repeated CT in this group.

CONCLUSIONS

Use and costs increased for most conditions except neoplasms and mental and behavioural disorders. More strategic CT use may have occurred in musculoskeletal conditions, while use and radiation burden increased for respiratory, circulatory and nervous system conditions. Using this high-level approach we flag areas requiring deeper investigation into appropriateness and value of care.

Assessing the effectiveness of artificial intelligence (AI) in prioritising CT head interpretation: study protocol for a stepped-wedge cluster randomised trial (ACCEPT-AI)

INTRODUCTION

Diagnostic imaging is vital in emergency departments (EDs). Accessibility and reporting impacts ED workflow and patient care. With radiology workforce shortages, reporting capacity is limited, leading to image interpretation delays. Turnaround times for image reporting are an ED bottleneck. Artificial intelligence (AI) algorithms can improve productivity, efficiency and accuracy in diagnostic radiology, contingent on their clinical efficacy. This includes positively impacting patient care and improving clinical workflow. The ACCEPT-AI study will evaluate Qure.ai's qER software in identifying and prioritising patients with critical findings from AI analysis of non-contrast head CT (NCCT) scans.

METHODS AND ANALYSIS

This is a multicentre trial, spanning four diverse sites, over 13 months. It will include all individuals above the age of 18 years who present to the ED, referred for an NCCT. The project will be divided into three consecutive phases (pre-implementation, implementation and post-implementation of the qER solution) in a stepped-wedge design to control for adoption bias and adjust for time-based changes in the background patient characteristics. Pre-implementation involves baseline data for standard care to support the primary and secondary outcomes. The implementation phase includes staff training and qER solution threshold adjustments in detecting target abnormalities adjusted, if necessary. The post-implementation phase will introduce a notification (prioritised flag) in the radiology information system. The radiologist can choose to agree with the qER findings or ignore it according to their clinical judgement before writing and signing off the report. Non-qER processed scans will be handled as per standard care.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the principles of Good Clinical Practice. The protocol was approved by the Research Ethics Committee of East Midlands (Leicester Central), in May 2023 (REC (Research Ethics Committee) 23/EM/0108). Results will be published in peer-reviewed journals and disseminated in scientific findings (ClinicalTrials.gov: NCT06027411) TRIAL REGISTRATION NUMBER: NCT06027411.

Diagnosis of acute aortic syndromes with ultrasound and d-dimer: the PROFUNDUS study

BACKGROUND

In patients complaining common symptoms such as chest/abdominal/back pain or syncope, acute aortic syndromes (AAS) are rare underlying causes. AAS diagnosis requires urgent advanced aortic imaging (AAI), mostly computed tomography angiography. However, patient selection for AAI poses conflicting risks of misdiagnosis and overtesting.

OBJECTIVES

We assessed the safety and efficiency of a diagnostic protocol integrating clinical data with point-of-care ultrasound (POCUS) and d-dimer (single/age-adjusted cutoff), to select patients for AAI.

METHODS

This prospective study involved 12 Emergency Departments from 5 countries. POCUS findings were integrated with a guideline-compliant clinical score, to define the integrated pre-test probability (iPTP) of AAS. If iPTP was high, urgent AAI was requested. If iPTP was low and d-dimer was negative, AAS was ruled out. Patients were followed for 30 days, to adjudicate outcomes.

RESULTS

Within 1979 enrolled patients, 176 (9 %) had an AAS. POCUS led to net reclassification improvement of 20 % (24 %/-4 % for events/non-events, P < 0.001) over clinical score alone. Median time to AAS diagnosis was 60 min if POCUS was positive vs 118 if negative (P = 0.042). Within 941 patients satisfying rule-out criteria, the 30-day incidence of AAS was 0 % (95 % CI, 0-0.41 %); without POCUS, 2 AAS were potentially missed. Protocol rule-out efficiency was 48 % (95 % CI, 46-50 %) and AAI was averted in 41 % of patients. Using age-adjusted d-dimer, rule-out efficiency was 54 % (difference 6 %, 95 % CI, 4-9 %, vs standard cutoff).

CONCLUSIONS

The integrated algorithm allowed rapid triage of high-probability patients, while providing safe and efficient rule-out of AAS. Age-adjusted d-dimer maximized efficiency.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT04430400.

What is the appropriate measure of radiology workload: Study or image numbers?

INTRODUCTION

Previous studies assessing the volume of radiological studies rarely considered the corresponding number of images. We aimed to quantify the increases in study and image numbers per radiologist in a tertiary healthcare network to better understand the demands on imaging services.

METHODS

Using the Picture Archiving and Communication System (PACS), the number of images per study was obtained for all diagnostic studies reported by in-house radiologists at a tertiary healthcare network in Melbourne, Australia, between January 2009 and December 2022. Payroll data was used to obtain the numbers of full-time equivalent radiologists.

RESULTS

Across all modalities, there were 4,462,702 diagnostic studies and 1,116,311,209 images. The number of monthly studies increased from 17,235 to 35,152 (104%) over the study period. The number of monthly images increased from 1,120,832 to 13,353,056 (1091%), with computed tomography (CT) showing the greatest absolute increase of 9,395,653 images per month (1476%). There was no increase in the monthly studies per full-time equivalent radiologist; however, the number of monthly image slices per radiologist increased 399%, from 48,781 to 243,518 (Kendall Tau correlation coefficient 0.830, P-value < 0.0001).

CONCLUSION

The number of monthly images per radiologist increased substantially from 2009 to 2022, despite a relatively constant number of monthly studies per radiologist. Our study suggests that using the number of studies as an isolated fundamental data set underestimates the true radiologist's workload. We propose that the increased volume of images examined by individual radiologists may more appropriately reflect true work demand and may add more weight to future workforce planning.

Patient perspectives on ionising radiation exposure from computed tomography in Saudi Arabia: a knowledge and perception study

The objective of this study was to evaluate patient knowledge and understanding of ionising radiation and dosage, as well as the accompanying risks related to computed tomography scans. A total of 412 outpatients who underwent computed tomography (CT) scans were surveyed to assess their understanding of radiation dose and exposure risks. CT was correctly classified as an ionising radiation by 56.8% of the respondents. More than half of the patients reported that a CT scan increases the probability of inducing cancer. Awareness of varying radiation doses in different CT exams was noted in 75.2% of patients, but only 21.4% reported having discussions with their physician about radiation dose. Gender, age and employment were significantly correlated with knowledge levels. The survey findings indicate a limited understanding of the hazards associated with ionising radiation used in CT scans, highlighting a need for increased awareness and education on radiation protection to ensure informed consent.

Patterns of computed tomography utilisation in injury management: latent classes approach using linked administrative data in Western Australia

PURPOSE

Whilst computed tomography (CT) imaging has been a vital component of injury management, its increasing use has raised concern regarding ionising radiation exposure. This study aims to identify latent classes (underlying patterns) of CT use over a 3-year period following the incidence of injury and factors predicting the observed patterns.

METHOD

A retrospective observational cohort study was conducted in 21,544 individuals aged 18 + years presenting to emergency departments (ED) of four tertiary public hospitals with new injury in Western Australia. Mixture modelling approach was used to identify latent classes of CT use over a 3-year period post injury.

RESULTS

Amongst injured people with at least one CT scan, three latent classes of CT use were identified including a: temporarily high CT use (46.4%); consistently high CT use (2.6%); and low CT use class (51.1%). Being 65 + years or older, having 3 + comorbidities, history with 3 + hospitalisations and history of CT use before injury were associated with consistently high use of CT. Injury to the head, neck, thorax or abdomen, being admitted to hospital after the injury and arriving to ED by ambulance were predictors for the temporarily high use class. Living in areas of higher socio-economic disadvantage was a unique factor associated with the low CT use class.

CONCLUSIONS

Instead of assuming a single pattern of CT use for all patients with injury, the advanced latent class modelling approach has provided more nuanced understanding of the underlying patterns of CT use that may be useful for developing targeted interventions.

Use of CT, ED presentation and hospitalisations 12 months before and after a diagnosis of cancer in Western Australia: a population-based retrospective cohort study

OBJECTIVE

To examine the use of CT, emergency department (ED)-presentation and hospitalisation and in 12 months before and after a diagnosis of cancer.

DESIGN

Population-based retrospective cohort study.

SETTING

West Australian linked administrative records at individual level.

PARTICIPANTS

104 009 adults newly diagnosed with cancer in 2004-2014.

MAIN OUTCOME MEASURES

CT use, ED presentations, hospitalisations.

RESULTS

As compared with the rates in the 12th month before diagnosis, the rate of CT scans started to increase from 2 months before diagnosis with an increase in both ED presentations and hospitalisation from 1 month before the diagnosis. These rates peaked in the month of diagnosis for CT scans (477 (95% CI 471 to 482) per 1000 patients), and for hospitalisations (910 (95% CI 902 to 919) per 1000 patients), and the month prior to diagnosis for ED (181 (95% CI 178 to 184) per 1000 patients) then rapidly reduced after diagnosis but remained high for the next 12 months. While the patterns of the health services used were similar between 2004 and 2014, the rate of the health services used during after diagnosis was higher in 2014 versus 2004 except for CT use in patients with lymphohaematopoietic cancer with a significant reduction.

CONCLUSION

Our results showed an increase in demand for health services from 2 months before diagnosis of cancer. Increasing use of health services during and post cancer diagnosis may warrant further investigation to identify factors driving this change.

The Great Contrast Shortage of 2022-Lessons learnt in Australia

INTRODUCTION

Computed tomography (CT) imaging is one of the most commonly used diagnostic tools. Iodine-based contrast media (IBCM) are frequently administered intravenously to improve soft tissue contrast in a wide range of CT scans. Supply chain disruptions triggered by the SARS-CoV-19 pandemic led to a global shortage of IBCM in mid-2022. The purpose of this study was to explore the impact of this shortage on the delivery of healthcare in Western Australia.

METHODS

We performed a single-centre retrospective analysis of the provision of CT studies, comparing historical patterns to the shortage period. We focussed our attention on the total number of CT scans (noncontrast CT [NCCT] and contrast-enhanced CT [CECT]) and also specifically CT pulmonary angiogram (CTPA) and CT neck angiogram with or without inclusion of circle of Willis (CTNA) examinations. We also examined whether a decrease was compensated by increasing frequency of alternate examinations such as ventilation/perfusion (V/Q) scans, carotid Doppler ultrasound studies and Magnetic Resonance Angiograms (MRAs).

RESULTS

Since 2012, there has been an approximate linear increase in the frequency of CT examinations. During the period of contrast shortage, there was an abrupt drop-off by approximately 50% in the CECT, CTPA and CTNA groups compared with the preceding 6 weeks (49%, 55% and 44%, respectively, with P < 0.001 in all cases). During the contrast shortage, the frequency of V/Q scans increased fivefold (from 13 to 65; P < 0.001). However, the provision of carotid Doppler ultrasound studies and MRAs remained approximately stable in frequency across recent time intervals.

CONCLUSION

Our findings demonstrate that the IBCM shortage crisis had a very significant impact on the delivery of healthcare. While V/Q scans could (partially) substitute for CTPA studies in suspected pulmonary emboli, there appeared to be no valid alternative for CTNA studies in stroke calls. The unexpected and critical shortage of IBCM forced healthcare professionals to conserve resources, prioritise indications, triage patients based on risk, explore alternate imaging strategies and prepare for similar events recurring in the future.

Automatic head computed tomography image noise quantification with deep learning

PURPOSE

Computed tomography (CT) image noise is usually determined by standard deviation (SD) of pixel values from uniform image regions. This study investigates how deep learning (DL) could be applied in head CT image noise estimation.

METHODS

Two approaches were investigated for noise image estimation of a single acquisition image: direct noise image estimation using supervised DnCNN convolutional neural network (CNN) architecture, and subtraction of a denoised image estimated with denoising UNet-CNN experimented with supervised and unsupervised noise2noise training approaches. Noise was assessed with local SD maps using 3D- and 2D-CNN architectures. Anthropomorphic phantom CT image dataset (N = 9 scans, 3 repetitions) was used for DL-model comparisons. Mean square error (MSE) and mean absolute percentage errors (MAPE) of SD values were determined using the SD values of subtraction images as ground truth. Open-source clinical head CT low-dose dataset (N_train = 37, N_test = 10 subjects) were used to demonstrate DL applicability in noise estimation from manually labeled uniform regions and in automated noise and contrast assessment.

RESULTS

The direct SD estimation using 3D-CNN was the most accurate assessment method when comparing in phantom dataset (MAPE = 15.5%, MSE = 6.3HU). Unsupervised noise2noise approach provided only slightly inferior results (MAPE = 20.2%, MSE = 13.7HU). 2DCNN and unsupervised UNet models provided the smallest MSE on clinical labeled uniform regions.

CONCLUSIONS

DL-based clinical image assessment is feasible and provides acceptable accuracy as compared to true image noise. Noise2noise approach may be feasible in clinical use where no ground truth data is available. Noise estimation combined with tissue segmentation may enable more comprehensive image quality characterization.

The Utilization and National Variation of Plain X-Ray Services by Australian Residents of Long-Term Care Facilities

OBJECTIVES

To (1) estimate incidence, trends, and determinants of government-subsidized diagnostic radiography (ie, plain x-ray) services utilization by Australian long-term care facility (LTCF) residents between 2009 and 2016; (2) examine national variation in services use.

DESIGN

A repeated cross-sectional study.

SETTING AND PARTICIPANTS

Australian LTCF residents who were ≥65 years old.

METHODS

Medicare Benefits Schedule subsidized plain x-rays employed for diagnosing fall-related injuries, pneumonia, heart failure, and acute abdomen or bowel obstruction were identified. Yearly sex- and age-standardized utilization rates were calculated. Poisson and negative binomial regression models were employed. Facility-level variation was examined graphically. Overall and examination site-specific analyses were conducted.

RESULTS

A total of 521,497 LTCF episodes for 453,996 individuals living in 3018 LTCFs were examined. The median age was 84 years (interquartile range 79-88), 65% (n = 339,116) were women, and 53.9% (n = 281,297) had dementia. In addition, 34.5% (n = 341,6863) of episodes had at least 1 x-ray service. Overall, there was a 12% increase in utilization between 2009 and 2016 (from 535/1000 in 2009 to 602/1000 person-years in 2016, incidence rate ratio=1.02, 95% CI 1.02-1.02). Factors associated with x-ray use included being 80-89 years old, being a man, not having dementia, having multiple health conditions (4-6 or ≥7 compared to 0-3), being at a smaller facility (0-24 bed compared to 50-74), facility located in the Australian state of New South Wales, or in major cities (compared to regional areas). National variation in x-ray service use, with largest differences observed by state, was detected.

CONCLUSIONS AND IMPLICATIONS

Plain x-ray service utilization by LTCF residents increased 12% between 2009 and 2016. Sex, age, dementia status, having multiple health conditions as well as facility size, and location were associated with plain x-ray use in LTCFs and use varied geographically. Differences in x-ray service utilization by residents highlight lack of consistent access and potential over- or underutilization.

The Incidence and Associated Risk Factors of Contrast-Induced Nephropathy after Contrast-Enhanced Computed Tomography in the Emergency Setting: A Systematic Review

Iodinated contrast media (ICM) during contrast-enhanced computed tomography (CECT) in the emergency department (ED) is essential to diagnose acute conditions, despite risks of contrast-induced nephropathy (CIN) development and its associated complications. This systematic review aims to evaluate the incidence of CIN and CIN-induced complications, and to explore the relevance of classical risk factors for CIN among ED patients receiving ICM. PubMed, Cochrane, and Web of Science were used on 30 August 2021 to search for peer-reviewed English articles reporting on CIN incidence among ED patients aged ≥18 years who underwent an intravenous CECT. The inclusion criteria included studies that were in English, peer-reviewed, and involved ED patients aged ≥18 years who underwent single intravenous CECT. Studies on intra-arterial procedures and preventive strategies, meta-analyses, clinical guidelines, review articles, and case reports were excluded. The JBI critical appraisal checklist was applied to assess the risk of bias. In total, 18 studies were included wherein 15 were retrospective studies while three were prospective studies. We found a relatively higher CIN incidence in the ED, with variations owing to the CIN definitions. Several classical risk factors including acute hypotension remain linked to CIN onset in ED settings unlike factors such as age and diabetes. While risk of adverse renal events due to CIN is low, there is higher risk of CIN-induced mortality in the ED. Therefore, with the higher incidence of CIN and CIN-induced mortality rates in the ED, ICM administration during CECT in the ED should still be clinically justified after assessing both benefits and risks.

Trend in CT utilisation and its impact on length of stay, readmission and hospital mortality in Western Australia tertiary hospitals: an analysis of linked administrative data 2003-2015

OBJECTIVE

High use of CT scanning has raised concern due to the potential ionising radiation exposure. This study examined trends of CT during admission to tertiary hospitals and its associations with length of stay (LOS), readmission and mortality.

DESIGN

Retrospective observational study from 2003 to 2015.

SETTING

West Australian linked administrative records at individual level.

PARTICIPANTS

2 375 787 episodes of tertiary hospital admission in adults aged 18+ years.

MAIN OUTCOME MEASURES

LOS, 30-day readmissions and mortality stratified by CT use status (any, multiple (CTs to multiple areas during episode), and repeat (repeated CT to the same area)).

METHODS

Multivariable regression models were used to calculate adjusted rate of CT use status. The significance of changes since 2003 in the outcomes (LOS, 30-day readmission and mortality) was compared among patients with specific CT imaging status relative to those without.

RESULTS

Between 2003 and 2015, while the rate of CT increased 3.4% annually, the rate of repeat CTs significantly decreased -1.8% annually and multiple CT showed no change. Compared with 2003 while LOS had a greater decrease in those with any CT, 30-day readmissions had a greater increase among those with any CT, while the probability of mortality remained unchanged between the any CT/no CT groups. A similar result was observed in patients with multiple and repeat CT scanning, except for a significant increase in mortality in the recent years in the repeat CT group.

CONCLUSION

The observed pattern of increase in CT utilisation is likely to be activity-based funding policy-driven based on the discordance between LOS and readmissions. Meanwhile, the repeat CT reduction aligns with a more selective strategy of use based on clinical severity. Future research should incorporate in-hospital and out-of-hospital CT to better understand overall CT trends and potential shifts between settings over time.

The use of computed tomography in the management of injury in tertiary emergency departments in Western Australia: Evidence of overtesting?

BACKGROUND

This study investigated trends in computed tomography (CT) utilization across different triage categories of injury presentations to tertiary emergency departments (EDs) and associations with diagnostic yield measured by injury severity, hospitalization and length of stay (LOS), and mortality.

METHODS

A total of 411,155 injury-related ED presentations extracted from linked records from Western Australia from 2004 to 2015 were included in the retrospective study. The use of CT scanning and diagnostic yield measured by rate of diagnosis with severe injury, hospitalizations and LOS, and mortality were captured annually for injury-related ED presentations. Multivariable regression models were used to calculate the annual adjusted rate of CT scanning for injury presentations and hospitalizations across triage categories, diagnosis with severe injury, LOS, and mortality. The significance of changes observed was compared among patients with CT imaging relative to those without CT.

RESULTS

While the number of ED presentations with injury increased by 65% from 2004 to 2015, the use of CT scanning in these presentations increased by 176%. The largest increase in CT use was among ED presentations triaged as semi-/nonurgent (+256%). Injury presentations with CT, compared to those without, had a higher rate of diagnosis with moderate/severe injury and hospitalization but no difference in LOS and mortality. The probability/rate observed in the outcomes of interest had a greater decrease over time in those with CT scanning compared with those without CT scanning across triage categories.

CONCLUSIONS

The reduction in diagnostic yield in terms of injury severity and hospitalization found in our study might indicate a shift toward overtesting using CT in ED for injury or a higher use of CT to assist in the management of injuries. This helps health care policymakers consider whether the current increase in CT use meets the desired levels of quality and efficient care.

Lipoma of the Pancreas: A Rare Incidental Tumor

Recent studies have shown a significant increase in the utilization of computed tomography (CT) scans in the emergency department for a broad spectrum of conditions. This had a significant impact on the identification of patients with serious pathologies in a timely manner. However, the overutilization of computed tomography scans leads to increased identification of incidental findings. For example, pancreatic lesions are not uncommon findings that can be identified in imaging studies performed for other indications. Here, we report the case of a 55-year-old male with a history of urinary stone disease who presented with right flank pain and dysuria. The urinalysis findings revealed numerous red blood cells and leukocytes. Non-contrast computed tomography scan of the abdomen was performed to detect urinary stones, but no hyperdense stones were noted, suggesting the possibility of spontaneous passage of the stone. However, a lesion in the pancreatic tail was observed. This exhibited fat attenuation with no solid component in the pancreatic tail representing a pancreatic lipoma. No surgical intervention was made considering the benign nature of the incidentally detected tumor. Pancreatic lipoma is a very rare benign mesenchymal tumor of the pancreas. Recognition of the classic radiological feature of pancreatic lipoma is essential to avoid unnecessary investigation and procedures.

Variability of redundant scan coverages along the Z-axis and dose implications for common computed tomography examinations

BACKGROUND

Scan length optimization is a method of optimization which ensures that, imaging is performed to cover just the area of interest without unnecessarily exposing structures that would not add value to answer a given clinical question.

PURPOSE

This study assessed the variability and degree of redundant scan coverages along the z-axis of CT examinations of common indications and the associated radiation dose implications in CT facilities in Ghana for optimization measures to be recommended.

METHODS

On reconstructed acquired CT images, the study measured extra distances covered above and below anatomical targets for common indications with calibrated calipers across 25 CT facilities. The National Cancer Institute Dosimetry System for CT (NCICT) (Monte Carlo-based-software) was used to simulate the scanning situations and organ dose implications for scans with and without the inclusion of the redundant scan areas.

RESULTS

A total of 1,640 patients' CT data sets were used in this study. The results demonstrated that CT imaging utilized varying scan lengths (16.45±21.0-45.99±4.3 cm), and 70.6% of the scans exceeded their pre-defined anatomic boundaries by a mean range of 2.86±1.07-5.81±1.66 cm, thereby resulting in extra patient radiation dose. Hence, scanning without the redundant coverages could generate a dose length product (DLP) reduction of 17.5%, 18.8%, 15.5% and 9.0% without degrading image quality for brain lesion, lung lesion, pulmonary embolism and abdominopelvic lesion CT imaging, respectively, whilst ensuring organ dose reduction of0.8%-79.1%.

CONCLUSION

The study strongly recommends that radiographers should avoid the inclusion of redundant areas in CT examinations to reduce organ doses.

Justification des demandes de tomodensitométrie aux urgences

Introduction : La justification des demandes de tomodensitométrie (TDM) faites aux urgences est mal connue. Notre objectif était d’évaluer la justification des demandes de TDM dans un service d’urgences adultes.

Méthodes : La justification des demandes de scanner a été mesurée prospectivement de deux façons complémentaires. L’adéquation aux recommandations a été évaluée pour l’ensemble des demandes de TDM par confrontation à une liste préétablie de syndromes et d’hypothèses diagnostiques. La pertinence des demandes a été évaluée par un comité d’experts sur la base du dossier médical des urgences pour 100 de ces dossiers.

Résultats : Les 273 TDM incluses concernaient le crâne (52%), l’abdomen (17%), le thorax (11%) ou une autre localisation (20%). Elles étaient en adéquation avec les recommandations dans 215 cas (79%). Pour 100 dossiers analysés par le comité d’experts, la pertinence a été adjugée à l’unanimité pour 95 cas ; 67 TDM (71%) ont été jugées pertinentes. La concordance entre l’adéquation aux recommandations et la pertinence évaluée par le comité d’expert était faible (kappa, 0,27, intervalle de confiance à 95%, de 0,06 à 0,47). Le seul facteur associé significativement à la pertinence était l’opinion du clinicien en charge du patient que la TDM ne pouvait pas être reportée (OR=6,7 avec IC95% [1,6-28,1], p=0,01).

Conclusion : La proportion des demandes de TDM qui ne sont pas en adéquation avec les recommandations et la proportion de demandes non pertinentes sont élevées. Elles suggèrent que le nombre de TDM demandées par les services d’urgences pourrait être diminué.