The Prognostic Capacity of the Radiographic Assessment for Lung Edema Score in Patients With COVID-19 Acute Respiratory Distress Syndrome—An International Multicenter Observational Study

Background: The radiographic assessment for lung edema (RALE) score has an association with mortality in patients with acute respiratory distress syndrome (ARDS). It is uncertain whether the RALE scores at the start of invasive ventilation or changes thereof in the next days have prognostic capacities in patients with COVID-19 ARDS.Aims and Objectives: To determine the prognostic capacity of the RALE score for mortality and duration of invasive ventilation in patients with COVID-19 ARDS.Methods: An international multicenter observational study included consecutive patients from 6 ICUs. Trained observers scored the first available chest X-ray (CXR) obtained within 48 h after the start of invasive ventilation (“baseline CXR”) and each CXRs thereafter up to day 14 (“follow-up CXR”). The primary endpoint was mortality at day 90. The secondary endpoint was the number of days free from the ventilator and alive at day 28 (VFD-28).Results: A total of 350 CXRs were scored in 139 patients with COVID-19 ARDS. The RALE score of the baseline CXR was high and was not different between survivors and non-survivors (33 [24–38] vs. 30 [25–38], P = 0.602). The RALE score of the baseline CXR had no association with mortality (hazard ratio [HR], 1.24 [95% CI 0.88–1.76]; P = 0.222; area under the receiver operating characteristic curve (AUROC) 0.50 [0.40–0.60]). A change in the RALE score over the first 14 days of invasive ventilation, however, had an independent association with mortality (HR, 1.03 [95% CI 1.01–1.05]; P < 0.001). When the event of death was considered, there was no significant association between the RALE score of the baseline CXR and the probability of being liberated from the ventilator (HR 1.02 [95% CI 0.99–1.04]; P = 0.08).Conclusion: In this cohort of patients with COVID-19 ARDS, with high RALE scores of the baseline CXR, the RALE score of the baseline CXR had no prognostic capacity, but an increase in the RALE score in the next days had an association with higher mortality.

Deep Learning-Based Four-Region Lung Segmentation in Chest Radiography for COVID-19 Diagnosis

Imaging plays an important role in assessing the severity of COVID-19 pneumonia. Recent COVID-19 research indicates that the disease progress propagates from the bottom of the lungs to the top. However, chest radiography (CXR) cannot directly provide a quantitative metric of radiographic opacities, and existing AI-assisted CXR analysis methods do not quantify the regional severity. In this paper, to assist the regional analysis, we developed a fully automated framework using deep learning-based four-region segmentation and detection models to assist the quantification of COVID-19 pneumonia. Specifically, a segmentation model is first applied to separate left and right lungs, and then a detection network of the carina and left hilum is used to separate upper and lower lungs. To improve the segmentation performance, an ensemble strategy with five models is exploited. We evaluated the clinical relevance of the proposed method compared with the radiographic assessment of the quality of lung edema (RALE) annotated by physicians. Mean intensities of segmented four regions indicate a positive correlation to the regional extent and density scores of pulmonary opacities based on the RALE. Therefore, the proposed method can accurately assist the quantification of regional pulmonary opacities of COVID-19 pneumonia patients.

Radiographic Assessment of the Feline Temporomandibular Joint with Oblique Projections: A Preliminary Ex Vivo Study

Radiographic assessment of the temporomandibular joint in the domestic cat using conventional radiographic views can be challenging due to superimposition of overlying structures and the complex anatomy of the skull. The use of computed tomography, magnetic resonance imaging, and cone beam computed tomography to assess the temporomandibular joint in the cat has increased, but these modalities are not always available in general veterinary practices. Conventional radiography is still commonly used for first line assessment of the temporomandibular joint. The aim of this preliminary study was to determine optimal angle of obliquity of lateroventral-laterodorsal and laterorostral-laterocaudal (nose up lateral oblique) oblique radiographic views in the assessment of the temporomandibular joints in five feline mesaticephalic dry skulls. Visibility of the mandibular head, mandibular fossa, retroarticular process, and temporomandibular joint space were evaluated and scored by two veterinary radiologists. The results of this study identified that the dependent temporomandibular joint anatomy was best seen on the latero-10°-ventral-laterodorsal, latero-15°-ventral-laterodorsal, and latero-20°-ventral-laterodorsal, oblique views, and opposite lateral oblique views at these angulations may be helpful in characterization of this anatomy in clinical patients. The results also indicate that the laterorostral-laterocaudal (nose up lateral oblique) oblique view did not allow adequate discrimination of all TMJ anatomy at any angle, and is not recommended.

Chest X-ray Severity and its Association with Outcomes in Patients with COVID-19 Presenting to the Emergency Department

Background: Severity of radiographic abnormalities on chest X-ray (CXR) in patients with COVID-19 has been shown to be associated with worse outcomes, but studies are limited by different scoring systems, sample size, patient age and study duration. Data regarding the longitudinal evolution of radiographic abnormalities and its association with outcomes is scarce. We sought to evaluate these questions using a well-validated scoring system (the Radiographic Assessment of Lung Edema [RALE] score) using data over 6 months from a large, multi-hospital healthcare system. Methods: We collected clinical and demographic data and quantified radiographic edema on CXRs obtained in the emergency department (ED) as well as on days 1-2 and 3-5 (in those admitted) in patients with a nasopharyngeal swab positive for SARS-CoV-2 PCR visiting the ED for COVID-19-related complaints between March and September 2020. We examined the association of baseline and longitudinal evolution of radiographic edema with severity of hypoxemia and clinical outcomes. Results: 870 patients were included (median age 53.6, 50.8% female). Inter-rate agreement for RALE scores was excellent (ICC = 0.84, 95% CI 0.82 - 0.87, p < 0.0001). RALE scores correlated with hypoxemia as quantified by SpO2-FiO2 ratio (r = -0.42, p < 0.001). Admitted patients had higher RALE scores than those discharged (6 [2, 11] vs 0 [0, 3], p < 0.001). An increase of RALE score of 4 or more was associated with worse 30-day survival (p < 0.01). Larger increases in the RALE score were associated with worse survival. Conclusions: The RALE score is reproducible and easily implementable in adult patients presenting to the ED with COVID-19. Its association with physiologic parameters and outcomes at baseline and longitudinally makes it a readily available tool for prognostication and early ICU triage, particularly in patients with worsening radiographic edema.