Using the Textual Content of Radiological Reports to Detect Emerging Diseases: A Proof-of-Concept Study of COVID-19.

Changes in the content of radiological reports at population level could detect emerging diseases. Herein, we developed a method to quantify similarities in consecutive temporal groupings of radiological reports using natural language processing, and we investigated whether appearance of dissimilarities between consecutive periods correlated with the beginning of the COVID-19 pandemic in France. CT reports from 67,368 consecutive adults across 62 emergency departments throughout France between October 2019 and March 2020 were collected. Reports were vectorized using time frequency-inverse document frequency (TF-IDF) analysis on one-grams. For each successive 2-week period, we performed unsupervised clustering of the reports based on TF-IDF values and partition-around-medoids. Next, we assessed the similarities between this clustering and a clustering from two weeks before according to the average adjusted Rand index (AARI). Statistical analyses included (1) cross-correlation functions (CCFs) with the number of positive SARS-CoV-2 tests and advanced sanitary index for flu syndromes (ASI-flu, from open-source dataset), and (2) linear regressions of time series at different lags to understand the variations of AARI over time. Overall, 13,235 chest CT reports were analyzed. AARI was correlated with ASI-flu at lag = + 1, + 5, and + 6 weeks (P = 0.0454, 0.0121, and 0.0042, respectively) and with SARS-CoV-2 positive tests at lag = - 1 and 0 week (P = 0.0057 and 0.0001, respectively). In the best fit, AARI correlated with the ASI-flu with a lag of 2 weeks (P = 0.0026), SARS-CoV-2-positive tests in the same week (P < 0.0001) and their interaction (P < 0.0001) (adjusted R2 = 0.921). Thus, our method enables the automatic monitoring of changes in radiological reports and could help capturing disease emergence.

Early prenatal diagnosis of causative homozygous variants in ASCC1 in a fetus with cystic hygroma and additional homozygous variants of unknown significance associated with a neurological phenotype not visible in early gestation: Dual diagnosis or not?

A consanguineous couple was referred at 10 weeks of gestation (WG) for prenatal genetic investigations due to isolated cystic hygroma. Prenatal trio exome sequencing identified causative homozygous truncating variants in ASCC1 previously implicated in spinal muscular atrophy with congenital bone fractures. Prenatal manifestations in ASCC1 can usually include hydramnios, fetal hypo-/akinesia, arthrogryposis, contractures and limb deformities, hydrops fetalis and cystic hygroma. An additional truncating variant was identified in CSPP1 associated with Joubert syndrome. Presentations in CSPP1 include cerebellar and brainstem malformations with vermis hypoplasia and molar tooth sign, difficult to visualize in early gestation. A second pregnancy was marked by the recurrence of isolated increased nuchal translucency at 10 + 2 WG. Sanger prenatal diagnosis targeted on ASCC1 and CSPP1 variants showed the presence of the homozygous familial ASCC1 variant. In this case, prenatal exome sequencing analysis is subject to a partial ASCC1 phenotype and an undetectable CSPP1 phenotype at 10 weeks of gestation. As CSPP1 contribution is unclear or speculative to a potentially later in pregnancy or postnatal phenotype, it is mentioned as a variant of uncertain significance. The detection of pathogenic or likely pathogenic variants involved in severe disorders but without phenotype-genotype correlation because the pregnancy is in the early stages or due to prenatally undetectable phenotypes, will encourage the clinical community to define future practices in molecular prenatal reporting.

Emergency department CT examinations demonstrate no evidence of early viral circulation at the start of the COVID-19 pandemic-a multicentre epidemiological study.

BACKGROUND: Biological studies suggested that the COVID-19 outbreak in France occurred before the first official diagnosis on January 24, 2020. We investigated this controversial topic using a large collection of chest CTs performed throughout French emergency departments within 6 months before the 1st lockdown. RESULTS: Overall, 49,311 consecutive patients (median age: 60 years, 23,636/49,311 [47.9%] women) with available chest CT images and reports from 61 emergency departments between September 1, 2020, and March 16, 2020 (day before the 1st French lockdown), were retrospectively included in this multicentre study. In the macroscopic analysis of reports automatically (labelled for presence of ground glass opacities [GGOs], reticulations, and bilateral and subpleural abnormalities), we found a significant breakpoint on February 17, 2020, for the weekly time series with 1, 2 and ≥ 3 of these 4 radiological features, with 146/49,311 (0.3%) patients showing bilateral abnormalities and ground glass opacities (GGOs) from that day. According to radiologists, 22/146 (15.1%) CT images showed typical characteristics of COVID-19, including 4/146 (2.7%) before February 2020. According to hospital records, one patient remained without microbial diagnosis, two patients had proven influenza A and one patient had concomitant influenza A and mycoplasma infection. CONCLUSION: These results suggest that SARS-CoV-2 was not circulating in the areas covered by the 61 emergency departments involved in our study before the official beginning of the COVID-19 outbreak in France. In emergency patients, the strong resemblance among mycoplasma, influenza A and SARS-CoV-2 lung infections on chest CT and the nonspecificity of CT patterns in low prevalence periods is stressed. CRITICAL RELEVANCE STATEMENT: We proposed here an innovative approach to revisit a controversial 'real' start of the COVID-19 pandemic in France based on (1) a population-level approach combining text mining, time series analysis and an epidemiological dataset and (2) a patient-level approach with careful retrospective reading of chest CT scans complemented by analysis of samples performed contemporarily to the chest CT. We showed no evidence that SARS-CoV-2 was actively circulating in France before February 2020.

Performance of the Fresno-Quebec Rule in identifying patients with concomitant fractures not requiring a radiograph before shoulder dislocation reduction: a multicenter retrospective cohort study.

BACKGROUND AND IMPORTANCE: Although shoulder dislocation diagnosis is often solely based on clinical examination, physicians may order a radiograph to rule out a concomitant shoulder fracture before performing reduction. The Fresno-Québec decision rule aims to identify patients requiring a radiograph before reduction to avoid unnecessary systematic imaging. However, this novel approach needs further validation. OBJECTIVE: To evaluate the performance of the Fresno-Québec rule in identifying patients who do not require a prereduction radiograph and assess the variables associated with a clinically significant fracture. DESIGN, SETTINGS, AND PARTICIPANTS: A multicenter, retrospective cohort study from 2015 to 2021. Data were extracted from three ED university-affiliated tertiary-care centers. Patients aged ≥18 years with a final diagnosis of anterior glenohumeral dislocation were included. OUTCOMES MEASURE AND ANALYSIS: Accuracy metrics [sensitivity (Se), specificity (Sp), positive (PPV), negative predictive value (NPV), positive likelihood ratio (PLR) and negative likelihood ratio (NLR)] of the Fresno-Québec rule were measured. Multivariable logistic regression model was used to identify variables associated with the presence of a concomitant clinically significant fracture. MAIN RESULTS: A total of 2129 patients were included, among whom 9.7% had a concomitant fracture. The performance metrics of the Fresno-Québec rule were as follows: Se 0.96 95% confidence interval (0.92-0.98), Sp 0.36 (0.34-0.38), PPV 0.14 (0.12-0.16), NPV 0.99 (0.98-0.99), PLR 1.49 (1.42-1.55) and NLR 0.12 (0.06-0.23). A total of 678 radiographs could have been avoided, corresponding to a reduction of 35.2%. Age ≥40 years, first dislocation episode [odds ratio (OR) = 3.18 (1.95-5.38); P  < 0.001], the following mechanisms: road collision [OR = 6.26 (2.65-16.1)], low-level fall [OR = 3.49 (1.66-8.28)], high-level fall [OR = 3.95 (1.62-10.4)], and seizure/electric shock [OR = 10.6 (4.09-29.2)] were associated with the presence of a concomitant fracture. CONCLUSION: In this study, the Fresno-Québec rule has excellent Se in identifying concomitant clinically significant fractures in patients with an anterior glenohumeral dislocation. The use of this clinical decision rule may be associated with a reduction of approximately a third of unnecessary prereduction radiographs.

Risk Factors Associated with Traumatic Brain Injury and Implementation of Guidelines for Requesting Computed Tomography After Head Trauma Among Children in France.

Importance: Pediatric traumatic brain injuries (TBIs) are a leading cause of death and disability. The Pediatric Emergency Care Applied Research Network (PECARN) guidelines provide a framework for requesting head computed tomography (HCT) after pediatric head trauma (PHT); however, quantitative data are lacking regarding both TBIs found on HCT and justification of the HCT request according to the PECARN guidelines. Objectives: To evaluate the types, frequencies, and risk factors for TBIs on HCT in children referred to emergency departments (EDs) who underwent HCT for PHT and to evaluate quality of HCT request. Design, Setting, and Participants: This multicenter, retrospective cohort study included patients younger than 18 years who underwent HCT for PHT who were referred to 91 EDs during on-call hours between January 1, 2020, to May 31, 2022. Data were analyzed between July and August 2022. Exposure: All radiological reports with pathologic findings were reviewed by 4 senior radiologists. Six hundred HCT requests filled by emergency physicians were randomly sampled to review the examination justification according to the PECARN guidelines. Main Outcomes and Measures: Associations between TBIs, age, sex, and Glasgow Coma Scale (GCS) were investigated using univariable χ2 and Cochrane-Armitage tests. Multivariable stepwise binary logistic regressions were used to estimate the odds ratio (ORs) for intracranial hemorrhages (ICH), any type of fracture, facial bone fracture, and skull vault fracture. Results: Overall, 5146 children with HCT for PHT were included (median [IQR] age, 11.2 [4.7-15.7] years; 3245 of 5146 [63.1%] boys). ICHs were diagnosed in 306 of 5146 patients (5.9%) and fractures in 674 of 5146 patients (13.1%). The following variables were associated with ICH in multivariable analysis: GCS score of 8 or less (OR, 5.83; 95% CI, 1.97-14.60; P < .001), extracranial hematoma (OR, 2.54; 95% CI, 1.59-4.02; P < .001), skull base fracture (OR, 9.32; 95% CI, 5.03-16.97; P < .001), upper cervical fracture (OR, 19.21; 95% CI, 1.79-143.59; P = .006), and skull vault fracture (OR, 35.64; 95% CI, 24.04-53.83; P < .001). When neither extracranial hematoma nor fracture was found on HCT, the OR for presenting ICH was 0.034 (95% CI, 0.026-0.045; P < .001). Skull vault fractures were more frequently encountered in children younger than 2 years (multivariable OR, 6.31; 95% CI, 4.16-9.66; P < .001; reference: children ≥12 years), whereas facial bone fractures were more frequently encountered in boys older than 12 years (multivariable OR, 26.60; 95% CI, 9.72-109.96; P < .001; reference: children younger than 2 years). The justification for performing HCT did not follow the PECARN guidelines for 396 of 589 evaluable children (67.2%) for requests filled by emergency physicians. Conclusion and Relevance: In this cohort study of 5146 children who underwent HCT for PHT, knowing the odds of clinical and radiological features for ICHs and fractures could help emergency physicians and radiologists improve their image analysis and avoid missing significant injuries. The PECARN rules were not implemented in nearly two-thirds of patients.

Impact of Vaccination and the Omicron Variant on COVID-19-related Chest CT Findings: A Multicenter Study.

Background The SARS-CoV-2 Omicron variant has a higher infection rate than previous variants but results in less severe disease. However, the effects of Omicron and vaccination on chest CT findings are difficult to evaluate. Purpose To investigate the effect of vaccination status and predominant variant on chest CT findings, diagnostic scores, and severity scores in a multicenter sample of consecutive patients referred to emergency departments for proven COVID-19. Materials and Methods This retrospective multicenter study included adults referred to 93 emergency departments with SARS-CoV-2 infection according to a reverse-transcriptase polymerase chain reaction test and known vaccination status between July 2021 and March 2022. Clinical data and structured chest CT reports, including semiquantitative diagnostic and severity scores following the French Society of Radiology-Thoracic Imaging Society guidelines, were extracted from a teleradiology database. Observations were divided into Delta-predominant, transition, and Omicron-predominant periods. Associations between scores and variant and vaccination status were investigated with χ2 tests and ordinal regressions. Multivariable analyses evaluated the influence of Omicron variant and vaccination status on the diagnostic and severity scores. Results Overall, 3876 patients were included (median age, 68 years [quartile 1 to quartile 3 range, 54-80]; 1695 women). Diagnostic and severity scores were associated with the predominant variant (Delta vs Omicron, χ2 = 112.4 and 33.7, respectively; both P < .001) and vaccination status (χ2 = 243.6 and 210.1; both P < .001) and their interaction (χ2 = 4.3 [P = .04] and 28.7 [P < .001], respectively). In multivariable analyses, Omicron variant was associated with lower odds of typical CT findings than was Delta variant (odds ratio [OR], 0.46; P < .001). Two and three vaccine doses were associated with lower odds of demonstrating typical CT findings (OR, 0.32 and 0.20, respectively; both P < .001) and of having high severity score (OR, 0.47 and 0.33, respectively; both P < .001), compared with unvaccinated patients. Conclusion Both the Omicron variant and vaccination were associated with less typical chest CT manifestations of COVID-19 and lesser extent of disease. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Yoon and Goo in this issue.

Emergency whole-body CT scans in pediatric patients with trauma: patterns of injuries, yield of dual-phase scanning, and influence of second read on detection of injuries.

OBJECTIVES: To describe injury patterns in children with multiple trauma (MT), evaluate the yield of dual-phase whole-body CT (WBCT), and quantify missed injuries detected on second reading. METHODS: Remotely analyzed WBCT performed between 2011 and 2020 in 63 emergency departments on children admitted for MT were included. Second reading occurred within 24 h. Collected data included age, sex, mechanism, Injury Severity Score (ISS), radiologists' experience, time and duration of first reading, conclusion of both readings, and dosimetry. Melvin score assessed the clinical impact of missed injuries. RESULTS: Overall, 1114 patients were included, 1982 injuries were described in 662 patients (59.4%), 452/1114 (40.6%) WBCT were negative, and 314 (28.2%) patients had MT (≥ 2 body parts injured). The most frequent injuries were pulmonary contusions (8.3%), costal fractures (6.2%), and Magerl A1 vertebral fractures (4.9%). Overall, 151 injuries were missed in 92 (8.3%) patients. Independent predictors for missed injuries were age ≤ 4 years (p = 0.03), number of injured body parts ≥ 2 (p = 0.01), and number of injuries ≥ 3 (p < 0.001). Melvin score grade 3 lesions were found in 16/92 (17.4%) patients with missed injuries (1.4% of all WBCT), where only prolonged follow-up was necessary. Thirteen active bleeding or pseudoaneurysms were detected (0.7% of injuries). CONCLUSION: Injuries were diagnosed in 59.4% of patients. Double-reading depicted additional injuries in 8.3% of patients, significantly more in children ≤ 4 years, with ≥ 3 injuries or ≥ 2 injured body parts. As 28 % of patients had MT and 1.1% had active extravasation or pseudoaneurysm, indication for WBCT should be carefully weighted. KEY POINTS: • When performed as a first-line imaging evaluation, approximately 41% of WBCT for MT children were considered normal. • The three most common injuries were pulmonary contusions, costal fractures, and Magerl A1 vertebral fractures, but the patterns of traumatic injuries on WBCT depended on the children's age and the trauma mechanism. • The independent predictors of missed injuries were age ≤ 4 years, number of body parts involved ≥ 2, and total number of injuries ≥ 3.

Prenatal quantification of human foetal lung and liver elasticities between 24 and 39 weeks of gestation using 2D shear wave elastography.

OBJECTIVES: To quantify and model normal foetal lung and liver elasticities between 24 and 39 weeks of gestation (WG) using two-dimensional shear wave elastography (2D-SWE). To assess the impact of the distance between the probe and the target organ on the estimation of elasticity values. METHODS: Measurements of normal foetal lungs and liver elasticity were prospectively repeated monthly between 24 and 39 WG in 72 foetuses using 2D-SWE. Elasticity was quantified in the proximal lung and in the region inside the hepatic portal sinus. The distance between the probe and the target organ was recorded. Trajectories representing foetal lung and liver maturation from at least 3 measurements over time were modelled. RESULTS: The average elasticity for the lung and liver was significantly different from 24 WG to 36 WG (p < 0.01). Liver elasticity increased during gestation (3.86 kPa at 24 WG versus 4.45 kPa at 39 WG). From 24 WG to 32 WG, lung elasticity gradually increased (4.12kPa at 24 WG, 4.91kPa at 28 WG, 5.03kPa at 32 WG, p < 0.002). After 32 WG, lung elasticity decreased to 4.54kPa at 36 WG and 3.94kPa at 39 WG. The dispersion of the average elasticity values was greater for the lung than for the liver (p < 0.0001). Variation in the elasticity values was less important for the liver than for the lung. The values were considered valid and repeatable except for a probe-lung distance above 8cm. CONCLUSION: Foetal lung and liver elasticities evolve differently through gestation. This could reflect the tissue maturation of both organs during gestation. TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT03834805 KEY POINTS: • Prenatal quantification of foetal lung elasticity using 2D shear wave elastography could be a new prenatal parameter for exploring foetal lung maturity. • Liver elasticity increased progressively from 24 weeks of gestation (WG) to 39 WG, while lung elasticity increased first between 24 and 32 WG and then decreased after 32 WG. • The values of elasticity are considered valid and repeatable except for a probe-lung distance above 8cm.

How artificial intelligence improves radiological interpretation in suspected pulmonary embolism.

OBJECTIVES: To evaluate and compare the diagnostic performances of a commercialized artificial intelligence (AI) algorithm for diagnosing pulmonary embolism (PE) on CT pulmonary angiogram (CTPA) with those of emergency radiologists in routine clinical practice. METHODS: This was an IRB-approved retrospective multicentric study including patients with suspected PE from September to December 2019 (i.e., during a preliminary evaluation period of an approved AI algorithm). CTPA quality and conclusions by emergency radiologists were retrieved from radiological reports. The gold standard was a retrospective review of CTPA, radiological and clinical reports, AI outputs, and patient outcomes. Diagnostic performance metrics for AI and radiologists were assessed in the entire cohort and depending on CTPA quality. RESULTS: Overall, 1202 patients were included (median age: 66.2 years). PE prevalence was 15.8% (190/1202). The AI algorithm detected 219 suspicious PEs, of which 176 were true PEs, including 19 true PEs missed by radiologists. In the cohort, the highest sensitivity and negative predictive values (NPVs) were obtained with AI (92.6% versus 90% and 98.6% versus 98.1%, respectively), while the highest specificity and positive predictive value (PPV) were found with radiologists (99.1% versus 95.8% and 95% versus 80.4%, respectively). Accuracy, specificity, and PPV were significantly higher for radiologists except in subcohorts with poor-to-average injection quality. Radiologists positively evaluated the AI algorithm to improve their diagnostic comfort (55/79 [69.6%]). CONCLUSION: Instead of replacing radiologists, AI for PE detection appears to be a safety net in emergency radiology practice due to high sensitivity and NPV, thereby increasing the self-confidence of radiologists. KEY POINTS: • Both the AI algorithm and emergency radiologists showed excellent performance in diagnosing PE on CTPA (sensitivity and specificity ≥ 90%; accuracy ≥ 95%). • The AI algorithm for PE detection can help increase the sensitivity and NPV of emergency radiologists in clinical practice, especially in cases of poor-to-moderate injection quality. • Emergency radiologists recommended the use of AI for PE detection in satisfaction surveys to increase their confidence and comfort in their final diagnosis.

What Influences the Way Radiologists Express Themselves in Their Reports? A Quantitative Assessment Using Natural Language Processing.

Although using standardized reports is encouraged, most emergency radiological reports in France remain in free-text format that can be mined with natural language processing for epidemiological purposes, activity monitoring or data collection. These reports are obtained under various on-call conditions by radiologists with various backgrounds. Our aim was to investigate what influences the radiologists' written expressions. To do so, this retrospective multicentric study included 30,227 emergency radiological reports of computed tomography scans and magnetic resonance imaging involving exactly one body region, only with pathological findings, interpreted from 2019-09-01 to 2020-02-28 by 165 radiologists. After text pre-processing, one-word tokenization and use of dictionaries for stop words, polarity, sentiment and uncertainty, 11 variables depicting the structure and content of words and sentences in the reports were extracted and summarized to 3 principal components capturing 93.7% of the dataset variance. In multivariate analysis, the 1st principal component summarized the length and lexical diversity of the reports and was significantly influenced by the weekday, time slot, workload, number of examinations previously interpreted by the radiologist during the on-call period, type of examination, emergency level and radiologists' gender (P value range: < 0.0001-0.0029). The 2nd principal component summarized negative formulations, polarity and sentence length and was correlated with the number of examination previously interpreted by the radiologist, type of examination, emergency level, imaging modality and radiologists' experience (P value range: < 0.0001-0.0032). The last principal component summarized questioning, uncertainty and polarity and was correlated with the type of examination and emergency level (all P values < 0.0001). Thus, the length, structure and content of emergency radiological reports were significantly influenced by organizational, radiologist- and examination-related characteristics, highlighting the subjectivity and variability in the way radiologists express themselves during their clinical activity. These findings advocate for more homogeneous practices in radiological reporting and stress the need to consider these influential features when developing models based on natural language processing.

Can fetal magnetic resonance imaging aid prognosis in gastroschisis: A multicenter study.

OBJECTIVE: To assess the contribution and impact of fetal magnetic resonance imaging (MRI) in managing fetal gastroschisis. METHODS: We conducted an observational retrospective study of gastroschisis patients at three fetal medicine centers from 2008 to 2019. The primary endpoint was the number of cases in which the MRI provided relevant information related to gastroschisis. RESULTS: A total of 189 patients were included, and our study group included 38 patients who underwent MRI. For the eight patients with suspected gastroschisis, MRI confirmed the diagnosis. In six cases, it provided additional relevant information (spiral turn, intestine ischemia, and bowel size discrepancy). For the 17 patients with ultrasound signs of additional gastrointestinal anomalies, MRI detected one case of unidentified complex gastroschisis on sonography. For the 13 patients undergoing routine MRI, no significant information was obtained. One termination of pregnancy and one fetoscopy were performed a few days after the MRI results. There was no subsequent follow-up or additional bowel complications to support management. CONCLUSION: Although MRI did not change the management of pregnancies complicated by fetal gastroschisis, patients presenting with fetal gastroschisis with intraabdominal bowel dilatation could benefit from MRI to allow for more precise prenatal counseling to predict postnatal intestinal complications before birth.

Pictorial review of the postmortem computed tomography in neonaticide cases.

Neonaticide is defined by the deliberate killing or homicide of a child within 24 h of its birth. In this context, three fundamental questions are generally asked of the forensic pathologist: what is the cause of death of the neonate? Was the child viable (i.e., what is the gestational age of the neonate)? Finally, was the neonate stillborn or liveborn?Postmortem imaging can help answer these questions by conducting (1) a complete lesional analysis of the body and the placenta, (2) an estimation of the gestational age by measuring the lengths of the diaphyseal long bones, and (3) an analysis of the aeration of the lungs and intestines. Using the details of 18 cases, we illustrate aspects of neonaticide cases in postmortem computed tomography (PMCT), offering detailed examples of notable postmortem changes and abnormalities, especially in the analysis of the pulmonary parenchyma. This article presents a useful iconography for the radiologist confronted with this rare yet complex forensic situation.

Emergency teleradiological activity is an epidemiological estimator and predictor of the covid-19 pandemic in mainland France.

BACKGROUND: COVID-19 pandemic highlighted the need for real-time monitoring of diseases evolution to rapidly adapt restrictive measures. This prospective multicentric study aimed at investigating radiological markers of COVID-19-related emergency activity as global estimators of pandemic evolution in France. We incorporated two sources of data from March to November 2020: an open-source epidemiological dataset, collecting daily hospitalisations, intensive care unit admissions, hospital deaths and discharges, and a teleradiology dataset corresponding to the weekly number of CT-scans performed in 65 emergency centres and interpreted remotely. CT-scans specifically requested for COVID-19 suspicion were monitored. Teleradiological and epidemiological time series were aligned. Their relationships were estimated through a cross-correlation function, and their extremes and breakpoints were compared. Dynamic linear models were trained to forecast the weekly hospitalisations based on teleradiological activity predictors. RESULTS: A total of 100,018 CT-scans were included over 36 weeks, and 19,133 (19%) performed within the COVID-19 workflow. Concomitantly, 227,677 hospitalisations were reported. Teleradiological and epidemiological time series were almost perfectly superimposed (cross-correlation coefficients at lag 0: 0.90-0.92). Maximal number of COVID-19 CT-scans was reached the week of 2020-03-23 (1 086 CT-scans), 1 week before the highest hospitalisations (23,542 patients). The best valid forecasting model combined the number of COVID-19 CT-scans and the number of hospitalisations during the prior two weeks and provided the lowest mean absolute percentage (5.09%, testing period: 2020-11-02 to 2020-11-29). CONCLUSION: Monitoring COVID-19 CT-scan activity in emergencies accurately and instantly predicts hospitalisations and helps adjust medical resources, paving the way for complementary public health indicators.

Computed Tomographic Changes in Patients with Cystic Fibrosis Treated by Combination Therapy with Lumacaftor and Ivacaftor.

BACKGROUND: As Cystic Fibrosis (CF) treatments drastically improved in recent years, tools to assess their efficiency need to be properly evaluated, especially cross-sectional imaging techniques. High-resolution computed tomography (HRCT) scan response to combined lumacaftor- ivacaftor therapy (Orkambi®) in patients with homozygous for F508del CFTR has not yet been assessed. METHODS: We conducted a retrospective observational study in two French reference centers in CF in Marseille hospitals, including teenagers (>12 years old) and adults (>18 years) who had received lumacaftor-ivacaftor and for whom we had at disposal at least two CT scans, one at before therapy and one at least six months after therapy start. CT scoring was performed by using the modified version of the Brody score. RESULTS: 34 patients have been included. The mean age was 26 years (12-56 years). There was a significant decrease in the total CT score (65.5 to 60.3, p = 0.049) and mucous plugging subscore (12.3 to 8.7, p = 0.009). Peribronchial wall thickening (PWT) was significantly improved only in the adult group (29.1 to 27.0, p = 0.04). Improvements in total score, peribronchial thickening, and mucous pluggings were significantly correlated with improvement in FEV1 (forced expiratory volume in 1 s). CONCLUSIONS: Treatment with lumacaftor-ivacaftor was associated with a significant improvement in the total CT score, which was mainly related to an improvement in mucous pluggings.

Practical clinical and radiological models to diagnose COVID-19 based on a multicentric teleradiological emergency chest CT cohort.

Our aim was to develop practical models built with simple clinical and radiological features to help diagnosing Coronavirus disease 2019 [COVID-19] in a real-life emergency cohort. To do so, 513 consecutive adult patients suspected of having COVID-19 from 15 emergency departments from 2020-03-13 to 2020-04-14 were included as long as chest CT-scans and real-time polymerase chain reaction (RT-PCR) results were available (244 [47.6%] with a positive RT-PCR). Immediately after their acquisition, the chest CTs were prospectively interpreted by on-call teleradiologists (OCTRs) and systematically reviewed within one week by another senior teleradiologist. Each OCTR reading was concluded using a 5-point scale: normal, non-infectious, infectious non-COVID-19, indeterminate and highly suspicious of COVID-19. The senior reading reported the lesions' semiology, distribution, extent and differential diagnoses. After pre-filtering clinical and radiological features through univariate Chi-2, Fisher or Student t-tests (as appropriate), multivariate stepwise logistic regression (Step-LR) and classification tree (CART) models to predict a positive RT-PCR were trained on 412 patients, validated on an independent cohort of 101 patients and compared with the OCTR performances (295 and 71 with available clinical data, respectively) through area under the receiver operating characteristics curves (AUC). Regarding models elaborated on radiological variables alone, best performances were reached with the CART model (i.e., AUC = 0.92 [versus 0.88 for OCTR], sensitivity = 0.77, specificity = 0.94) while step-LR provided the highest AUC with clinical-radiological variables (AUC = 0.93 [versus 0.86 for OCTR], sensitivity = 0.82, specificity = 0.91). Hence, these two simple models, depending on the availability of clinical data, provided high performances to diagnose positive RT-PCR and could be used by any radiologist to support, modulate and communicate their conclusion in case of COVID-19 suspicion. Practically, using clinical and radiological variables (GGO, fever, presence of fibrotic bands, presence of diffuse lesions, predominant peripheral distribution) can accurately predict RT-PCR status.

Technical feasibility and correlations between shear-wave elastography and histology in kidney fibrosis in children.

BACKGROUND: Ultrasound elastography has been suggested for assessing organ fibrosis. OBJECTIVE: To study the feasibility of shear-wave elastography in children with kidney disease and the correlation between elasticity and kidney fibrosis in order to reduce the indications for kidney biopsy and its complications. MATERIALS AND METHODS: Four operators measured kidney elasticity in children with kidney diseases or transplants, all of whom also had a renal biopsy. We assessed the feasibility and the intraobserver variability of the elasticity measurements for each probe used and each kidney explored. Then we tested the correlation between elasticity measurements and the presence of fibrosis. RESULTS: Overall, we analyzed 95 children and adolescents, 31 of whom had renal transplant. Measurements with the convex probe were possible in 100% of cases. Linear probe analysis was only possible for 20% of native kidneys and 50% of transplants. Intraobserver variabilities ranged from moderate to high, depending on the probe and kidney studied. Elasticity was higher with the linear probe than with the convex probe (P<0.001 for left kidney and P=0.03 for right kidney). Measurements did not differ from one kidney to another in the same child. Elasticity and fibrosis were both higher in transplant patients (P=0.02 with convex probe; P=0.01 with linear probe; P=0.04 overall). There was no correlation between elasticity and fibrosis. CONCLUSION: Of the devices used in this work, kidney elastography was more accurately analyzed with a convex probe. Our study did not identify any correlation between elasticity and kidney fibrosis.

Teleradiology as a relevant indicator of the impact of COVID-19 pandemic management on emergency room activities: a nationwide worrisome survey.

OBJECTIVES: To evaluate the impact of COVID-19's lockdown on radiological examinations in emergency services. METHODS: Retrospective, multicentre analysis of radiological examinations requested, via our teleradiology network, from 2017 to 2020 during two timeframes (calendar weeks 5-8 and then 12-15). We included CT scans or MRIs performed for strokes, multiple traumas (Body-CT), cranial traumas (CTr) and acute non-traumatic abdominal pain (ANTAP). We evaluated the number and percentages of examinations performed, of those with a pathological conclusion, and of examinations involving the chest. RESULTS: Our study included 25 centres in 2017, 29 in 2018, 43 in 2019 and 59 in 2020. From 2017 to 2019, the percentages of examinations were constant, which was also true for chest CTs. Each centre's number of examinations, gender distribution and patient ages were unchanged. In 2020, examinations significantly decreased: suspected strokes decreased by 36% (1052 vs 675, p < 0.001), Body-CT by 62% (349 vs 134, p < 0.001), CTr by 52% (1853 vs 895, p < 0.001) and for ANTAP, appendicitis decreased by 38% (45 vs 90, not statistically significant (NS)) sigmoiditis by 44% (98 vs 55, NS), and renal colic by 23% (376 vs 288, NS). The number of examinations per centre decreased by 13% (185.5 vs 162.5, p < 0.001), whereas the number of examinations of the "chest" region increased by 170% (1205 vs 3766, p < 0.001). CONCLUSION: Teleradiology enabled us to monitor the impact of the COVID-19 pandemic management on emergency activities, showing a global decrease in the population's use of care.