[Diagnosis and emergency management of radiological incidents]. / Diagnostic et prise en charge en urgence des incidents radiologiques.

Incidents involving ionizing radiation pose a risk of immediate and long-term clinical consequences for both victims and responders in the event of secondary contamination. Rapid identification of the problem and a coordinated response are crucial. This article summarizes the key challenges related to the emergency management of a single patient or multiple victims, addressing the importance of recognizing such a case, radioprotection measures, decontamination, and available treatments.

Les incidents impliquant des rayonnements ionisants représentent un risque aux conséquences cliniques immédiates et à long terme, tant pour les victimes que pour les intervenants en cas de contamination secondaire. L'identification rapide de la problématique et une réponse coordonnée sont cruciales. Cet article résume les principaux enjeux liés à la prise en charge en urgence d'un patient unique ou de plusieurs victimes, en abordant l'importance de la reconnaissance d'un tel cas, des mesures de radioprotection, de la décontamination et des traitements disponibles.

Magnetic Resonance Imaging or Computed Tomography for Suspected Acute Stroke: Association of Admission Image Modality with Acute Recanalization Therapies, Workflow Metrics, and Outcomes.

OBJECTIVE: To examine rates of intravenous thrombolysis (IVT), mechanical thrombectomy (MT), door-to-needle (DTN) time, door-to-puncture (DTP) time, and functional outcome between patients with admission magnetic resonance imaging (MRI) versus computed tomography (CT). METHODS: An observational cohort study of consecutive patients using a target trial design within the nationwide Swiss-Stroke-Registry from January 2014 to August 2020 was carried out. Exclusion criteria included MRI contraindications, transferred patients, and unstable or frail patients. Multilevel mixed-effects logistic regression with multiple imputation was used to calculate adjusted odds ratios with 95% confidence intervals for IVT, MT, DTN, DTP, and good functional outcome (mRS 0-2) at 90 days. RESULTS: Of the 11,049 patients included (mean [SD] age, 71 [15] years; 4,811 [44%] women; 69% ischemic stroke, 16% transient ischemic attack, 8% stroke mimics, 6% intracranial hemorrhage), 3,741 (34%) received MRI and 7,308 (66%) CT. Patients undergoing MRI had lower National Institutes of Health Stroke Scale (median [interquartile range] 2 [0-6] vs 4 [1-11]), and presented later after symptom onset (150 vs 123 min, p < 0.001). Admission MRI was associated with: lower adjusted odds of IVT (aOR 0.83, 0.73-0.96), but not with MT (aOR 1.11, 0.93-1.34); longer adjusted DTN (+22 min [13-30]), but not with longer DTP times; and higher adjusted odds of favorable outcome (aOR 1.54, 1.30-1.81). INTERPRETATION: We found an association of MRI with lower rates of IVT and a significant delay in DTN, but not in DTP and rates of MT. Given the delays in workflow metrics, prospective trials are required to show that tissue-based benefits of baseline MRI compensate for the temporal benefits of CT. ANN NEUROL 2022;92:184-194.

An Update on Obstructive Sleep Apnea Syndrome-A Literature Review.

Obstructive sleep apnea syndrome (OSAS) is the most common breathing-related sleep disorder. It is characterized by recurrent episodes of partial or complete airway obstruction during sleep, resulting in a reduction in or the total cessation of airflow, despite ongoing respiratory efforts, leading to oxygen desaturation and arousal. The purpose of this literature review is to evaluate the most common characteristics of this pathology, as well as to investigate the most effective treatment options, providing an update on the management of OSA patients.

Development and Validation of a Predictive Model for Internal Hernia After Roux-en-Y Gastric Bypass in a Multicentric Retrospective Cohort: The Swirl, Weight Excess Loss, Liquid Score.

OBJECTIVE: The aim of this study was to develop and validate a prediction score for internal hernia (IH) after Roux-en-Y gastric bypass (RYGB). SUMMARY BACKGROUND DATA: The clinical diagnosis of IH is challenging. A sensitivity of 63% to 92% was reported for computed tomography (CT). METHODS: Consecutive patients admitted for abdominal pain after RYGB and undergoing CT and surgical exploration were included retrospectively. Potential clinical predictors and radiological signs of IH were entered in binary logistic regression analysis to determine a predictive score of surgically confirmed IH in the Geneva training set (January 2006-December 2014), and validated in 3 centers, Geneva (January 2015-December 2017) and Neuchâtel and Strasbourg (January 2012-December 2017). RESULTS: Two hundred twenty-eight patients were included, 80 of whom (35.5%) had surgically confirmed IH, 38 (16.6%) had a negative laparoscopy, and 110 (48.2%) had an alternate diagnosis. In the training set of 61 patients, excess body weight loss >95% (odds ratio [OR] 6.73, 95% confidence interval [CI]: 1.13-39.96), swirl sign (OR 8.93, 95% CI: 2.30-34.70), and free liquid (OR 4.53, 95% CI: 1.08-19.0) were independent predictors of IH. Area under the curve (AUC) of the score was 0.799. In the validation set of 167 patients, AUC was 0.846. A score ≥2 was associated with an IH incidence of 60.7% (34/56), and 5.3% (3/56) had a negative laparoscopy. CONCLUSIONS: The score could be incorporated in the clinical setting. To reduce the risk of delayed IH diagnosis, emergency explorative laparoscopy in patients with a score ≥ 2 should be considered.

Emergency Computed Tomography: How Misinterpretations Vary According to the Periods of the Nightshift?

OBJECTIVE: To evaluate the accuracy of initial computed tomography (CT) interpretations made by radiology residents during nightshifts in the emergency department. METHODS: Preliminary CT reports performed by radiology residents during 120 consecutive nightshifts (08:30 pm to 08:30 am) were reviewed, attendings' final interpretation being the reference standard. Nightshifts were divided into four consecutive periods of 3 hours. Major misinterpretations were related to potentially life-threatening conditions if not treated immediately after CT. The rate of misinterpretations was calculated for all CT examinations, separately for nightshift's periods and for residents' training years. RESULTS: Misinterpretations were recorded in 155 (7.4%) of 2102 CT examinations, 0.6% (13/2102) were major. There were 2.2% (4/186) major misinterpretations that occurred during the last period of the nightshift versus 0.4% (9/1916) during the first periods of the night (P < 0.05). Of all misinterpretations, 8.5% (130/1526) were made by third- and fourth-year residents and 4.3% (25/576) by fifth-year residents (P < 0.005). CONCLUSIONS: Major misinterpretations occur at the end of the nightshift, which may be explained by the fatigue effect. The rate of misinterpretations is lower among fifth-year residents, which may be related to their prior experience in reading emergency cases.

Clot-Based Radiomics Predict a Mechanical Thrombectomy Strategy for Successful Recanalization in Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Mechanical thrombectomy (MTB) is a reference treatment for acute ischemic stroke, with several endovascular strategies currently available. However, no quantitative methods are available for the selection of the best endovascular strategy or to predict the difficulty of clot removal. We aimed to investigate the predictive value of an endovascular strategy based on radiomic features extracted from the clot on preinterventional, noncontrast computed tomography to identify patients with first-attempt recanalization with thromboaspiration and to predict the overall number of passages needed with an MTB device for successful recanalization. METHODS: We performed a study including 2 cohorts of patients admitted to our hospital: a retrospective training cohort (n=109) and a prospective validation cohort (n=47). Thrombi were segmented on noncontrast computed tomography, followed by the automatic computation of 1485 thrombus-related radiomic features. After selection of the relevant features, 2 machine learning models were developed on the training cohort to predict (1) first-attempt recanalization with thromboaspiration and (2) the overall number of passages with MTB devices for successful recanalization. The performance of the models was evaluated on the prospective validation cohort. RESULTS: A small subset of radiomic features (n=9) was predictive of first-attempt recanalization with thromboaspiration (receiver operating characteristic curve-area under the curve, 0.88). The same subset also predicted the overall number of passages required for successful recanalization (explained variance, 0.70; mean squared error, 0.76; Pearson correlation coefficient, 0.73; P<0.05). CONCLUSIONS: Clot-based radiomics have the ability to predict an MTB strategy for successful recanalization in acute ischemic stroke, thus allowing a potentially better selection of the MTB strategy, as well as patients who are most likely to benefit from the intervention.

Suspicion of appendicitis in pregnant women: emergency evaluation by sonography and low-dose CT with oral contrast.

OBJECTIVES: To evaluate non-intravenously enhanced low-dose computed tomography with oral contrast (LDCT) for the assessment of pregnant women with right lower quadrant pain, when magnetic resonance imaging (MRI) is not immediately available. METHODS: One hundred and thirty-eight consecutive pregnant women with acute abdominal pain were admitted in our emergency centre. Thirty-seven (27%) of them, with clinical suspicion of acute appendicitis, underwent abdominal ultrasonography (US). No further examination was recommended when US was positive for appendicitis, negative with low clinical suspicion or showed an alternative diagnosis which explained the clinical presentation. All other patients underwent LDCT (<2.5 mSv). Standard intravenously enhanced CT or MRI was performed when LDCT was indeterminate. RESULTS: Eight (22%) of 37 US exams were reported normal, 25 (67%) indeterminate, 1 (3%) positive for appendicitis, 3 (8%) positive for an alternative diagnosis. LDCT was obtained in 29 (78%) patients. It was reported positive for appendicitis in 9 (31%), for alternative diagnosis in 2 (7%), normal in 13 (45%) and indeterminate in 5 (17%). Further imaging (standard CT or MRI) showed appendicitis in 2 of these 5 patients, was truly negative in 1, indeterminate in 1 and falsely positive in 1. An appendicitis was confirmed at surgery in 12 (32%) of the 37 patients. The sensitivity and the specificity of the algorithm for appendicitis were 100% (12/12) and 92% (23/25), respectively. CONCLUSIONS: The proposed algorithm is very sensitive and specific for detection of acute appendicitis in pregnant women; it reduces the need of standard CTs when MRI is not available as second-line imaging. KEY POINTS: • In pregnant women, US is limited by an important number of indeterminate results • Low-dose CT can be used after an inconclusive US for the diagnosis of appendicitis in pregnant women • An algorithm integrating US and low-dose CT is highly sensitive and specific for appendicitis in pregnant women.

Femoral head subchondral impaction on CT: what does it mean in patients with acetabular fracture?

OBJECTIVE: To evaluate the prevalence of isolated femoral head impactions associated with acetabular fractures and to assess whether impactions may be predictive of the development of delayed major complications requiring total hip arthroplasty. MATERIALS AND METHODS: A total of 128 consecutive adult patients with acetabular fracture and no femoral head fracture were included. Admission CTs were re-interpreted for the presence of hip dislocation and femoral head impactions. Radiological and clinical reports were reviewed in patients in whom conservative management of the femoral head was attempted, to determine if total hip arthroplasty was eventually required over a 48-month follow-up period. Univariate and multivariate analyses were performed to assess whether impaction is an independent predictor of failure of conservative management. RESULTS: Impaction was found in 40% of all patients (51 out of 128), in 58% of those with dislocation (19 out of 33), and in 34% of those without dislocation (32 out of 95; p < 0.05). One hundred and five patients underwent conservative management of the femoral head; 12.5% of them (13 out of 105) eventually required total hip arthroplasty. An impaction was present in 77% of the latter (10 out of 13) and in 33% of patients with successful conservative management (30 out of 92; p = 0.0042). At multivariate analysis, impaction and dislocation were significantly and independently associated with a higher risk for delayed total hip arthroplasty (odds ratio of 4.8 and 4.0 respectively). CONCLUSION: Femoral head impactions are frequently seen on CT of patients with acetabular fractures; they are independent predictive factors for the need for delayed total hip arthroplasty. They should be systematically mentioned in the CT report.

Concomitant leukocytosis and lymphopenia predict significant pathology at CT of acute abdomen: a case-control study.

BACKGROUND: Acute abdominal pain accounts for about 10% of emergency department visits and has progressively become the primary indication for CT scanning in most centers. The goal of our study is to identify biological or clinical variables able to predict or rule out significant pathology (conditions requiring urgent medical or surgical treatment) on abdominal CT in patients presenting to an emergency department with acute abdominal pain. METHODS: This was a retrospective cohort study performed in the emergency department of an academic center with an annual census of 60'000 patients. One hundred and-nine consecutive patients presenting with an acute non-traumatic abdominal pain, not suspected of appendicitis or renal colic, during the first semester of 2013, who underwent an abdominal CT were included. Two medical students, completing their last year of medical school, extracted the data from patients' electronic health record. Ambiguities in the formulations of clinical symptoms and signs in the patients' records were solved by consulting a board certified emergency physician. Nine clinical and biological variables were extracted: shock index, peritonism, abnormal bowel sounds, fever (> 38 °C), intensity and duration of the pain, leukocytosis (white blood cell count >11G/L), relative lymphopenia (< 15% of total leukocytes), and C-reactive Protein (CRP). These variables were compared to the CT results (reference standard) to determine their ability to predict a significant pathology. RESULTS: Significant pathology was detected on CT in 71 (65%) patients. Only leukocytosis (odds ratio 3.3, p = 0.008) and relative lymphopenia (odds ratio 3.8, p = 0.002) were associated with significant pathology on CT. The joint presence of these two anomalies was strongly associated with significant pathology on CT (odds ratio 8.2, p = 0.033). Leukocytosis with relative lymphopenia had a specificity of 89% (33/37) and sensitivity of 48% (33/69) for the detection of significant pathology on CT. CONCLUSION: The high specificity of the association between leukocytosis and relative lymphopenia amongst the study population suggests that these parameters would be sufficient to justify an emergency CT. However, none of the parameters could be used to rule out a significant pathology.

Assessment of CT dose to the fetus and pregnant female patient using patient-specific computational models.

PURPOSE: This work provides detailed estimates of the foetal dose from diagnostic CT imaging of pregnant patients to enable the assessment of the diagnostic benefits considering the associated radiation risks. MATERIALS AND METHODS: To produce realistic biological and physical representations of pregnant patients and the embedded foetus, we developed a methodology for construction of patient-specific voxel-based computational phantoms based on existing standardised hybrid computational pregnant female phantoms. We estimated the maternal absorbed dose and foetal organ dose for 30 pregnant patients referred to the emergency unit of Geneva University Hospital for abdominal CT scans. RESULTS: The effective dose to the mother varied from 1.1 mSv to 2.0 mSv with an average of 1.6 mSv, while commercial dose-tracking software reported an average effective dose of 1.9 mSv (range 1.7-2.3 mSv). The foetal dose normalised to CTDIvol varies between 0.85 and 1.63 with an average of 1.17. CONCLUSION: The methodology for construction of personalised computational models can be exploited to estimate the patient-specific radiation dose from CT imaging procedures. Likewise, the dosimetric data can be used for assessment of the radiation risks to pregnant patients and the foetus from various CT scanning protocols, thus guiding the decision-making process. KEY POINTS: • In CT examinations, the absorbed dose is non-uniformly distributed within foetal organs. • This work reports, for the first time, estimates of foetal organ-level dose. • The foetal brain and skeleton doses present significant correlation with gestational age. • The conceptus dose normalised to CTDI vol varies between 0.85 and 1.63. • The developed methodology is adequate for patient-specific CT radiation dosimetry.

Emergency assessment of patients with acute abdominal pain using low-dose CT with iterative reconstruction: a comparative study.

OBJECTIVES: To determine if radiation dose delivered by contrast-enhanced CT (CECT) for acute abdominal pain can be reduced to the dose administered in abdominal radiography (<2.5 mSv) using low-dose CT (LDCT) with iterative reconstruction algorithms. METHODS: One hundred and fifty-one consecutive patients requiring CECT for acute abdominal pain were included, and their body mass index (BMI) was calculated. CECT was immediately followed by LDCT. LDCT series was processed using 1) 40% iterative reconstruction algorithm blended with filtered back projection (LDCT-IR-FBP) and 2) model-based iterative reconstruction algorithm (LDCT-MBIR). LDCT-IR-FBP and LDCT-MBIR images were reviewed independently by two board-certified radiologists (Raters 1 and 2). RESULTS: Abdominal pathology was revealed on CECT in 120 (79%) patients. In those with BMI <30, accuracies for correct diagnosis by Rater 1 with LDCT-IR-FBP and LDCT-MBIR, when compared to CECT, were 95.4% (104/109) and 99% (108/109), respectively, and 92.7% (101/109) and 100% (109/109) for Rater 2. In patients with BMI ≥30, accuracies with LDCT-IR-FBP and LDCT-MBIR were 88.1% (37/42) and 90.5% (38/42) for Rater 1 and 78.6% (33/42) and 92.9% (39/42) for Rater 2. CONCLUSIONS: The radiation dose delivered by CT to non-obese patients with acute abdominal pain can be safely reduced to levels close to standard radiography using LDCT-MBIR. KEY POINTS: • LDCT-MBIR (<2.5 mSv) can be used to assess acute abdominal pain. • LDCT-MBIR (<2.5 mSv) cannot safely assess acute abdominal pain in obese patients. • LDCT-IR-FBP (<2.5 mSv) cannot safely assess patients with acute abdominal pain.

Emergency Computed Tomography: What is Missed at First Reading?

OBJECTIVES: The aim of this study was to evaluate the accuracy of preliminary computed tomography (CT) interpretations made by radiology residents in the emergency department. METHODS: For 4 periods of 20 consecutive days, attending radiologists prospectively recorded any disparities between their own CT interpretations (reference standard) and the preliminary interpretations of emergency radiology residents. Misinterpretations were defined as major when related to a potentially life-threatening pathology if not immediately managed after CT. The rate of disparities was calculated for all CT examinations, separately for body and neuroradiological cases, and for working and on-call hours. RESULTS: A total of 3044 emergency CT examinations were performed during the survey: 1568 (51%) body scans and 1476 (49%) neurological scans. Disparities were reported in 145 (4.8%) of all CT examinations, with 0.8% (24/3044) defined as major misinterpretations. There were 100 (6.3%) of 1568 disparities in body CT versus 45 (3.0%) of 1476 in neurological CT examinations (P = 0.001). No significant differences were found between disparities recorded during regular working hours (47/1083 [4.3%]) versus on-call hours (98/1961 [5.0%], P = 0.47). CONCLUSIONS: There were typically more disparities between resident and attending interpretations in emergency body CT. Major disparities represented only a small proportion of all misinterpretations. The detailed analysis of our data enables benchmarking over time and offers a reference for optimizing the training of residents in emergency radiology.

Illegal intra-corporeal packets: can dual energy CT be used for the evaluation of cocaine concentration? A cross sectional study.

BACKGROUND: The recent implementation of the dual energy technology on CT-scanners has opened new perspectives in tissue and material characterization. This study aims to evaluate whether dual energy CT can be used to assess the concentration of cocaine of intra-intestinal illegal packets. METHODS: The study was approved by the institutional review board of our institution (CER 13_027_R). From November 2010 to May 2013, all consecutive conveyors in whom a low-dose abdominal CT (LDCT) revealed the presence of illegal intra-corporeal drug packets underwent a dual energy CT series (gemstone spectral imaging) targeted on one container. The mean radiological density (HU) of these packets was measured on the LDCT series, and on the monochromatic dual energy series, at 40 and 140 keV. The difference between the HU at 40 and 140 keV was reported as ∆HU. The effective atomic number Z(eff) was also measured on the monochromatic series. A chemical analysis was performed after expulsion to select cocaine containing packets, and to determine their cocaine concentrations. A correlation analysis was performed between HU, ∆HU and Z(eff), with regard to the percentage of cocaine. RESULTS: Fifty-four cocaine conveyors were included. The mean cocaine content of the packets was 36.8% (range 11.2-80, SD 15.4), the mean radiologic density 105 HU, the mean Z(eff) 8.7 and the mean ∆HU 163. The cocaine content was correlated with the ∆HU (0.57, p < 0.001), with the Z(eff) (r = 0.56, p < 0.001) but not with radiologic density (r = 0.25, p = 0.064). ∆HU >200 was 0.9 (9 of 10) sensitive and 0.82 (36 of 44) specific to predict a cocaine concentration higher than 50%. CONCLUSION: Measuring ∆HU or Z(eff) on dual energy monochromatic CT series can be used to detect ingested packets with cocaine concentration >50%.

Dual-Energy CT in Acute Stroke: Could Non-Contrast CT Be Replaced by Virtual Non-Contrast CT? A Feasibility Study.

Purpose: We aimed to evaluate whether virtual non-contrast cerebral computed tomography (VNCCT) reconstructed from intravenous contrast-enhanced dual-energy CT (iv-DECT) could replace non-contrast CT (NCCT) in patients with suspected acute cerebral ischemia. Method: This retrospective study included all consecutive patients in whom NCCT followed by iv-DECT were performed for suspected acute ischemia in our emergency department over a 1-month period. The Alberta Stroke Program Early CT Score (ASPECTS) was used to determine signs of acute ischemia in the anterior and posterior circulation, the presence of hemorrhage, and alternative findings, which were randomly evaluated via the consensus reading of NCCT and VNCCT by two readers blinded to the final diagnosis. An intraclass correlation between VNCCT and NCCT was calculated for the ASPECTS values. Both techniques were evaluated for their ability to detect ischemic lesions (ASPECTS <10) when compared with the final discharge diagnosis (reference standard). Results: Overall, 148 patients (80 men, mean age 64 years) were included, of whom 46 (30%) presented with acute ischemia, 6 (4%) presented with intracerebral hemorrhage, 11 (7%) had an alternative diagnosis, and 85 (59%) had no pathological findings. The intraclass correlation coefficients of the two modalities were 0.97 (0.96-0.98) for the anterior circulation and 0.77 (0.69-0.83) for the posterior circulation. The VNCCT's sensitivity for detecting acute ischemia was higher (41%, 19/46) than that of NCCT (33%, 15/46). Specificity was similar between the two techniques, at 94% (97/103) and 98% (101/103), respectively. Conclusions: Our results show that VNCCT achieved a similar diagnostic performance as NCCT and could, thus, replace NCCT in assessing patients with suspected acute cerebral ischemia.

Validating the accuracy of deep learning for the diagnosis of pneumonia on chest x-ray against a robust multimodal reference diagnosis: a post hoc analysis of two prospective studies.

BACKGROUND: Artificial intelligence (AI) seems promising in diagnosing pneumonia on chest x-rays (CXR), but deep learning (DL) algorithms have primarily been compared with radiologists, whose diagnosis can be not completely accurate. Therefore, we evaluated the accuracy of DL in diagnosing pneumonia on CXR using a more robust reference diagnosis. METHODS: We trained a DL convolutional neural network model to diagnose pneumonia and evaluated its accuracy in two prospective pneumonia cohorts including 430 patients, for whom the reference diagnosis was determined a posteriori by a multidisciplinary expert panel using multimodal data. The performance of the DL model was compared with that of senior radiologists and emergency physicians reviewing CXRs and that of radiologists reviewing computed tomography (CT) performed concomitantly. RESULTS: Radiologists and DL showed a similar accuracy on CXR for both cohorts (p ≥ 0.269): cohort 1, radiologist 1 75.5% (95% confidence interval 69.1-80.9), radiologist 2 71.0% (64.4-76.8), DL 71.0% (64.4-76.8); cohort 2, radiologist 70.9% (64.7-76.4), DL 72.6% (66.5-78.0). The accuracy of radiologists and DL was significantly higher (p ≤ 0.022) than that of emergency physicians (cohort 1 64.0% [57.1-70.3], cohort 2 63.0% [55.6-69.0]). Accuracy was significantly higher for CT (cohort 1 79.0% [72.8-84.1], cohort 2 89.6% [84.9-92.9]) than for CXR readers including radiologists, clinicians, and DL (all p-values < 0.001). CONCLUSIONS: When compared with a robust reference diagnosis, the performance of AI models to identify pneumonia on CXRs was inferior than previously reported but similar to that of radiologists and better than that of emergency physicians. RELEVANCE STATEMENT: The clinical relevance of AI models for pneumonia diagnosis may have been overestimated. AI models should be benchmarked against robust reference multimodal diagnosis to avoid overestimating its performance. TRIAL REGISTRATION: NCT02467192 , and NCT01574066 . KEY POINT: • We evaluated an openly-access convolutional neural network (CNN) model to diagnose pneumonia on CXRs. • CNN was validated against a strong multimodal reference diagnosis. • In our study, the CNN performance (area under the receiver operating characteristics curve 0.74) was lower than that previously reported when validated against radiologists' diagnosis (0.99 in a recent meta-analysis). • The CNN performance was significantly higher than emergency physicians' (p ≤ 0.022) and comparable to that of board-certified radiologists (p ≥ 0.269).

Temporal Bone Fractures and Related Complications in Pediatric and Adult Cranio-Facial Trauma: A Comparison of MDCT Findings in the Acute Emergency Setting.

PURPOSE: The purpose of this study was to analyze the prevalence of and complications resulting from temporal bone fractures in adult and pediatric patients evaluated for cranio-facial trauma in an emergency setting. METHODS: A retrospective blinded analysis of CT scans of a series of 294 consecutive adult and pediatric patients with cranio-facial trauma investigated in the emergency setting was conducted. Findings were compared between the two populations. Preliminary reports made by on-call residents were compared with the retrospective analysis, which was performed in consensus by two experienced readers and served as reference standard. RESULTS: CT revealed 126 fractures in 116/294 (39.5%) patients, although fractures were clinically suspected only in 70/294 (23.8%); p < 0.05. Fractures were longitudinal, transverse and mixed in 69.5%, 10.3% and 19.8% of cases, respectively. Most fractures were otic-sparing fractures (95.2%). Involvement of the external auditory canal, ossicular chain and the osseous structures surrounding the facial nerve was present in 72.2%, 8.7% and 6.3% of cases, respectively. Temporal bone fractures extended into the venous sinuses/jugular foramen and carotid canal in 18.3% and 17.5% of cases, respectively. Vascular injuries (carotid dissection and venous thrombosis) were more common in children than in adults (13.6% versus 5.3%); however, the observed difference did not reach statistical significance. 79.5% of patients with temporal bone fractures had both brain injuries and fractures of the facial bones and cranial vault. Brain injuries were more common in adults (90.4%) than in children (63.6%), p = 0.001. Although on-call residents reliably detected temporal bone fractures (sensitivity = 92.8%), they often missed trauma-associated ossicular dislocation (sensitivity = 27.3%). CONCLUSIONS: Temporal bone fractures and related complications are common in patients with cranio-facial trauma and need to be thoroughly looked for; the pattern of associated injuries is slightly different in children and in adults.

MDCT in the assessment of laryngeal trauma: value of 2D multiplanar and 3D reconstructions.

OBJECTIVE: The purpose of this study was to analyze fracture patterns and related effects of laryngeal trauma and to assess the value of 2D multiplanar reformation (MPR) and 3D reconstruction. MATERIALS AND METHODS: Among 4222 consecutively registered trauma patients who underwent emergency MDCT, 38 patients had presented with laryngeal trauma. Axial, 2D MPR, 3D volume-rendered, and virtual endoscopic images were analyzed retrospectively by two blinded observers according to predefined criteria. Laryngeal fractures, soft-tissue injuries, and airway compromise were evaluated and correlated with clinical, endoscopic, surgical, and follow-up findings. RESULTS: Fifty-nine fractures (37 thyroid, 13 cricoid, nine arytenoid) were present in 38 patients. They were isolated in 21 (55%) patients. The other 17 (45%) patients had additional injuries to the neck, face, brain, chest, or abdomen. Laryngeal fractures were bilateral in 31 (82%) patients and were associated with hyoid bone fractures in nine (24%) patients. Arytenoid luxation was present in eight cartilages. Axial imaging missed 7 of 59 (12%) laryngeal fractures, six of eight (75%) arytenoid luxations, and four of nine (44%) hyoid bone fractures. Additional 2D MPR imaging missed 5 of 59 (8%) laryngeal fractures, five of eight (62.5%) arytenoid luxations, and two of nine (22%) hyoid bone fractures, whereas 3D volume-rendered images depicted them all. Virtual endoscopy and 3D volume rendering added diagnostic accuracy with respect to the length, width, shape, and spatial orientation of fractures in 22 of 38 (58%) patients; arytenoid luxation in six of eight (75%) luxations; and the evaluation of airway narrowing in 19 of 38 (50%) patients. Three-dimensional volume rendering was not of additional value in evaluation of the cricoid cartilage. CONCLUSION: The use of 2D MPR and 3D volume rendering with or without virtual endoscopy improved assessment of thyroid and hyoid bone fractures, arytenoid luxations, and laryngotracheal narrowing, providing helpful data for optimal management.

N-acetylcysteine does not prevent contrast nephropathy in patients with renal impairment undergoing emergency CT: a randomized study.

BACKGROUND: Patients admitted to the emergency room with renal impairment and undergoing a contrast computed tomography (CT) are at high risk of developing contrast nephropathy as emergency precludes sufficient hydration prior to contrast use. The value of an ultra-high dose of intravenous N-acetylcysteine in this setting is unknown. METHODS: From 2008 to 2010, we randomized 120 consecutive patients admitted to the emergency room with an estimated clearance lower than 60 ml/min/1.73 m2 by MDRD (mean GFR 42 ml/min/1.73 m2) to either placebo or 6000 mg N-acetylcysteine iv one hour before contrast CT in addition to iv saline. Serum cystatin C and creatinine were measured one hour prior to and at day 2, 4 and 10 after contrast injection. Nephrotoxicity was defined either as 25% or 44 µmol/l increase in serum creatinine or cystatin C levels compared to baseline values. RESULTS: Contrast nephrotoxicity occurred in 22% of patients who received placebo (13/58) and 27% of patients who received N-acetylcysteine (14/52, p = 0.66). Ultra-high dose intravenous N-acetylcysteine did not alter creatinine or cystatin C levels. No secondary effects were noted within the 2 groups during follow-up. CONCLUSIONS: An ultra-high dose of intravenous N-acetylcysteine is ineffective at preventing nephrotoxicity in patients with renal impairment undergoing emergency contrast CT. TRIAL REGISTRATION: The study was registered as Clinical trial (NCT01467154).

The role of unenhanced CT alone for the management of headache in an emergency department. A feasibility study.

OBJECTIVE: To determine whether unenhanced CT alone could be sufficient for the screening of patients admitted with a suspicion of secondary headache in an emergency center. MATERIAL AND METHODS: A feasibility study including consecutive patients admitted to our emergency department for acute non-traumatic headache, in whom a brain CT was required by the emergency physician, was conducted over a 3-month period of time. Patients with a suspicion of intracranial pathology, which can only be depicted by i.v. images (arterial dissection, venous thrombosis, or postoperative complication) were recorded but excluded from analysis. All patients underwent both unenhanced and i.v. enhanced cerebral CT, including CT angiography. Unenhanced CTs were reviewed by two radiologists, blinded to the clinical data, to the radiological reports and to the i.v. enhanced images. Unenhanced CT were sorted by the radiologists into three groups: (1) normal CT, (2) benign finding that could explain headache without need of injection of contrast media, (3) evidence of an intracranial pathology, requiring further imaging. Results were compared to i.v. enhanced CT images. RESULTS: A brain CT was required in 105 patients (34 males, 71 females) during the study period, 74 (70%) of them met our inclusion criteria. Fifty-nine (80%) were sorted in group 1 (normal), four (5%) in group 2, 11 (15%) in group 3. No further finding that could explain acute headache was found on i.v. CT images in patients of group 1 or 2. A significant pathology was confirmed by i.v. CT in all patients of group 3. CONCLUSION: This feasibility study suggests that a normal unenhanced CT might be sufficient to exclude the cause of headache in the initial screening of a selected group of patients admitted with cephalalgia. It compels researchers to perform further prospective studies to confirm the current data on a larger amount of patients.

Artificial intelligence-based opportunistic detection of coronary artery stenosis on aortic computed tomography angiography in emergency department patients with acute chest pain.

Aims: To evaluate a deep-learning model (DLM) for detecting coronary stenoses in emergency room patients with acute chest pain (ACP) explored with electrocardiogram-gated aortic computed tomography angiography (CTA) to rule out aortic dissection. Methods and results: This retrospective study included 217 emergency room patients (41% female, mean age 67.2 years) presenting with ACP and evaluated by aortic CTA at our institution. Computed tomography angiography was assessed by two readers, who rated the coronary arteries as 1 (no stenosis), 2 (<50% stenosis), or 3 (≥50% stenosis). Computed tomography angiography was categorized as high quality (HQ), if all three main coronary arteries were analysable and low quality (LQ) otherwise. Curvilinear coronary images were rated by a DLM using the same system. Per-patient and per-vessel analyses were conducted. One hundred and twenty-one patients had HQ and 96 LQ CTA. Sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of the DLM in patients with high-quality image for detecting ≥50% stenoses were 100, 62, 59, 100, and 75% at the patient level and 98, 79, 57, 99, and 84% at the vessel level, respectively. Sensitivity was lower (79%) for detecting ≥50% stenoses at the vessel level in patients with low-quality image. Diagnostic accuracy was 84% in both groups. All 12 patients with acute coronary syndrome (ACS) and stenoses by invasive coronary angiography (ICA) were rated 3 by the DLM. Conclusion: A DLM demonstrated high NPV for significant coronary artery stenosis in patients with ACP. All patients with ACS and stenoses by ICA were identified by the DLM.