Early chest CT-scan in emergency patients affected by community-acquired pneumonia is associated with improved diagnosis consistency.

Chest CT-scan (CT) exceeds chest X-ray (CXR) to diagnose community-acquired pneumonia (CAP) but actual use and results remain unclear. We examine whether CT performed at ED visit improved ED diagnosis of CAP as compared to a final diagnosis of CAP at hospital discharge (gold standard diagnosis for the study), and how it impacts relevant clinical outcomes. This retrospective monocenter observational study was based on the analysis of the hospital database. Patients with a diagnosis of CAP in the ED (ICD-10 codes: J110, J111, from J12- to J18-, J440, J690, U0710, and U0711) were included. We compared ED patients who were diagnosed with CAP using CXR and CT. We measured diagnostic consistency, duration of ED visit, percentage of CXR and CT during hospital stay, hospital length-of-stay, ICU admission, and in-hospital mortality. Multivariate analysis was adjusted for CRB65 score by multiple logistic regression analysis for binary outcomes and by multivariate analysis of variance for continuous outcomes. We included 994 ED patients with an initial diagnosis of CAP (751 receiving CXR, 243 receiving CT). CT prescription in the ED increased over time ( P < 0.001). In patients admitted after ED, CT improved diagnosis consistency for CAP [88.2% vs. 80.9%; difference 7.3% (95% confidence interval 1.2-13.3%)] with a trend for lower hospital length-of-stay [10.2 vs. 12.2 days; difference -2.0 (95% confidence interval -3.9 to -0.1)], but not ICU admission ( P = 0.09) and in-hospital mortality ( P = 0.056). Diagnosis of patients admitted with CAP improved when CT was obtained at ED visit. These results should be reproduced at a larger scale to test whether early CT conserves healthcare resources.

Microvascular injuries, secondary edema, and inconsistencies in lung vascularization between affected and nonaffected pulmonary segments of non-critically ill hospitalized COVID-19 patients presenting with clinical deterioration.

PURPOSE: We aimed to better understand the pathophysiology of SARS-CoV-2 pneumonia in non-critically ill hospitalized patients secondarily presenting with clinical deterioration and increase in oxygen requirement without any identified worsening factors. METHODS: We consecutively enrolled patients without clinical or biological evidence for superinfection, without left ventricular dysfunction and for whom a pulmonary embolism was discarded by computed tomography (CT) pulmonary angiography. We investigated lung ventilation and perfusion (LVP) by LVP scintigraphy, and, 24 h later, left and right ventricular function by Tc-99m-labeled albumin-gated blood-pool scintigraphy with late (60 mn) tomographic albumin images on the lungs to evaluate lung albumin retention that could indicate microvascular injuries with secondary edema. RESULTS: We included 20 patients with confirmed SARS-CoV-2 pneumonia. All had CT evidence of organizing pneumonia and normal left ventricular ejection fraction. No patient demonstrated preserved ventilation with perfusion defect (mismatch), which may discard a distal lung thrombosis. Patterns of ventilation and perfusion were heterogeneous in seven patients (35%) with healthy lung segments presenting a relative paradoxical hypoperfusion and hypoventilation compared with segments with organizing pneumonia presenting a relative enhancement in perfusion and preserved ventilation. Lung albumin retention in area of organizing pneumonia was observed in 12 patients (60%), indicating microvascular injuries, increase in vessel permeability, and secondary edema. CONCLUSION: In hospitalized non-critically ill patients without evidence of superinfection, pulmonary embolism, or cardiac dysfunction, various types of damage may contribute to clinical deterioration including microvascular injuries and secondary edema, inconsistencies in lung segments vascularization suggesting a dysregulation of the balance in perfusion between segments affected by COVID-19 and others. SUMMARY STATEMENT: Microvascular injuries and dysregulation of the balance in perfusion between segments affected by COVID-19 and others are present in non-critically ill patients without other known aggravating factors. KEY RESULTS: In non-critically ill patients without evidence of superinfection, pulmonary embolism, macroscopic distal thrombosis or cardiac dysfunction, various types of damage may contribute to clinical deterioration including 1/ microvascular injuries and secondary edema, 2/ inconsistencies in lung segments vascularization with hypervascularization of consolidated segments contrasting with hypoperfusion of not affected segments, suggesting a dysregulation of the balance in perfusion between segments affected by COVID-19 and others.

The Left Atrio-Vertebral Ratio: a new simple means for assessing left atrial enlargement on Computed Tomography.

OBJECTIVE: The purpose of this study is to describe a new method to quickly estimate left atrial enlargement (LAE) on Computed Tomography. METHODS: Left atrial (LA) volume was assessed with a 3D-threshold Hounsfield unit detection technique, including left atrial appendage and excluding pulmonary venous confluence, in 201 patients with ECG-gated 128-slice dual-source CT and indexed to body surface area. LA and vertebral axial diameter and area were measured at the bottom level of the right inferior pulmonary vein ostium. Ratio of LA diameter and surface on vertebra (LAVD and LAVA) were compared to LA volume. In accordance with the literature, a cutoff value of 78 ml/m2 was chosen for maximal normal LA volume. RESULTS: 18% of LA was enlarged. The best cutoff values for LAE assessment were 2.5 for LAVD (AUC: 0.65; 95% CI: 0.58-0.73; sensitivity: 57%; specificity: 71%), and 3 for LAVA (AUC: 0.78; 95% CI: 0.72-0.84; sensitivity: 67%; specificity: 79%), with higher accuracy for LAVA (P=0.015). Inter-observer and intra-observer variability were either good or excellent for LAVD and LAVA (respective intraclass coefficients: 0.792 and 0.910; 0.912 and 0.937). CONCLUSION: A left atrium area superior to three times the vertebral area indicates LAE with high specificity. KEY POINTS: • Left atrial enlargement is a frequent condition associated with poor cardiac outcome. • Left atrial enlargement is highly time-consuming to diagnose on CT. • The left atrio-vertebral ratio quickly assesses left atrial enlargement. • A left atrial area > three times vertebral area is highly specific.

Bronchocele density in cystic fibrosis as an indicator of allergic broncho-pulmonary aspergillosis: A preliminary study.

OBJECTIVE: Allergic broncho-pulmonary aspergillosis (ABPA) is a severe and under-diagnosed complication of cystic fibrosis (CF). The aim of the study was to determine whether the mucus content of bronchoceles in cystic fibrosis complicated with ABPA reveals a higher density than the mucus content of non-ABPA cystic fibrosis. MATERIALS AND METHODS: We studied retrospectively 43 computed tomography scans (CT scans) of a pediatric population of cystic fibrosis patients. We measured the mucus attenuation in Hounsfield Units (HU) of all bronchoceles >5mm in diameter. RESULTS: We found bronchoceles >5mm in 13/43 patients. 5/13 patients had a positive diagnosis of ABPA. The median HU value of bronchoceles was higher in patients with than without ABPA [98 HU (26-135) vs 28 HU (10-36); P=0,02]. Moreover, all patients with a bronchocele density >36HU were ABPA positive. CONCLUSIONS: CF complicated with ABPA shows higher attenuation bronchoceles on CT scans of the chest. Systematic density measurements of bronchoceles could help to raise the difficult diagnosis of ABPA in patients suffering from cystic fibrosis. Larger series could confirm a threshold in HU which could become a new imaging criterion for the diagnosis of ABPA.

Left atrio-vertebral ratio: A new computed-tomography measurement to identify left atrial dilation.

BACKGROUND: Left cardiac chambers dilation, interstitial lung changes and pleural effusions are the characteristics of cardiogenic pulmonary oedema on computed tomography (CT) of the chest but mensuration of the left atrial size is not routinely performed. Cardiac chambers normal dimensions are known to be proportional to the patient's build and anthropomorphic data but adjustment of chambers dimensions to available elements seen on the axial CT images has never been evaluated before. OBJECTIVES: Our objective was to use data easily available on axial images to directly scale the left atrium. We chose to divide the left atrial diameter by the thoracic vertebral diameter, using the latter as a body-mass indicator. As a preliminary study, we aimed to evaluate the range of values of this left atrio-vertebral ratio (LAVR) by comparing patients suffering from cardiogenic pulmonary oedema with patients free of cardiac disease. We hypothesized that if the difference of values in these two populations of patients was significant enough, this ratio would be relevant and could be used as a quick criterion in different clinical situations. METHOD: Two radiologists reviewed CT scans of 32 of patients free of cardiac disease and 40 patients in acute cardiac failure. The maximum diameter of the left atrium at the level of the right inferior pulmonary vein was divided by the vertebral transverse diameter to generate a left atrio-vertebral ratio. Receiver operating characteristic curves identified the threshold associated with pulmonary oedema. MEASUREMENTS AND MAIN RESULTS: The mean LAVR was 1.85 ± 0.27 in asymptomatic patients and 2.48 ± 0.35 in patients with pulmonary oedema. A LAVR of 2.1 yielded 85% sensitivity and 88% specificity for the diagnosis of cardiogenic pulmonary oedema. CONCLUSIONS: LAVR is a simple new measure directly scaling the left atrial diameter to the anthropomorphic characteristics of the patient. In our series, a ratio above 2.1 is strongly associated with cardiogenic pulmonary oedema indirectly suggesting left atrial dilation. The results were significantly different between the two populations of patients (no heart condition versus cardiogenic pulmonary oedema) suggesting a high potential for clinical application.

CT quantification of hemoperitoneum volume in abdominal haemorrhage: a new method.

INTRODUCTION: In emergency departments, focused assessment for sonographic examination of trauma patients (FAST) accurately detects hemoperitoneum in unstable patients. Currently, only an approximation of the volume of free intraperitoneal fluid (FIPF) can be done using ultrasound (US) and CT scans. We previously reported a new method developed on an experimental cadaveric model using US examination of the abdomen and applying a mathematic formula to effusion measurements to evaluate the exact volume of FIPF. The aim of this prospective study is to extrapolate this method in a clinical practice and apply it to CT measurements of the same area. PATIENTS AND METHODS: We included prospectively eleven patients admitted with acute intraperitoneal haemorrhage: 10 patients with post-traumatic hemoperitoneum and 1 patient with a ruptured extra-uterine pregnancy. The mean age was 43.2 years (extremes: 21-82). There were six males and five females. All of these patients had to undergo emergency surgery by laparotomy or laparoscopy. The amount of FIPF was assessed preoperatively on axial sections of CT scan, by measuring fluid thickness in millimetres in the hepatorenal pouch (Morrison's pouch), between the inferior aspect of the liver and the anterior aspect of the right kidney. During the emergency surgical procedure, we collected and quantified FIPF volume by direct measure in all cases. RESULTS: The correlation between fluid thickness x (mm) on the CT scan and the estimated amount of FIPF was established by the following linear function: volume (mL) = 81.068x + 263.2. The Spearman's R obtained is 0.779 and the significance level is 0.005. We found a constant correlation between FIPF measured by radiologic procedure and direct per-operative measurement of FIPF. CONCLUSION: This new linear function can be used to measure the exact volume of FIPF. This evaluation can help surgical decisions, especially when abdominal trauma is associated with other haemorrhagic lesions.