Early-stage COVID-19 pandemic observations on pulmonary embolism using nationwide multi-institutional data harvesting.

We introduce a multi-institutional data harvesting (MIDH) method for longitudinal observation of medical imaging utilization and reporting. By tracking both large-scale utilization and clinical imaging results data, the MIDH approach is targeted at measuring surrogates for important disease-related observational quantities over time. To quantitatively investigate its clinical applicability, we performed a retrospective multi-institutional study encompassing 13 healthcare systems throughout the United States before and after the 2020 COVID-19 pandemic. Using repurposed software infrastructure of a commercial AI-based image analysis service, we harvested data on medical imaging service requests and radiology reports for 40,037 computed tomography pulmonary angiograms (CTPA) to evaluate for pulmonary embolism (PE). Specifically, we compared two 70-day observational periods, namely (i) a pre-pandemic control period from 11/25/2019 through 2/2/2020, and (ii) a period during the early COVID-19 pandemic from 3/8/2020 through 5/16/2020. Natural language processing (NLP) on final radiology reports served as the ground truth for identifying positive PE cases, where we found an NLP accuracy of 98% for classifying radiology reports as positive or negative for PE based on a manual review of 2,400 radiology reports. Fewer CTPA exams were performed during the early COVID-19 pandemic than during the pre-pandemic period (9806 vs. 12,106). However, the PE positivity rate was significantly higher (11.6 vs. 9.9%, p < 10-4) with an excess of 92 PE cases during the early COVID-19 outbreak, i.e., ~1.3 daily PE cases more than statistically expected. Our results suggest that MIDH can contribute value as an exploratory tool, aiming at a better understanding of pandemic-related effects on healthcare.

COVID-19 ARDS: a review of imaging features and overview of mechanical ventilation and its complications.

The first cluster of cases of COVID-19 pneumonia was reported on December 31, 2019. Since then, this disease has spread rapidly across the world, and as of September 17, 2021, there are 226,844,344 cases of COVID-19 worldwide with 4,666,334 deaths related to COVID-19. While most COVID-19 cases are mild, some cases are severe with patients developing acute respiratory distress syndrome (ARDS). The pathophysiology of ARDS includes damage to the alveolar epithelium that leads to increased permeability of the alveolar epithelial barrier causing hyaline membrane formation, interstitial edema, and alveolar edema that results in severe hypoxia. Patients with COVID-19 ARDS are supported by non-invasive or invasive mechanical ventilation with an aim to improve oxygenation and maintain adequate blood oxygen levels. Increased intra-alveolar pressure while on mechanical ventilation may lead to alveolar rupture and thus barotrauma-related injuries such as lung tension cysts, pulmonary interstitial emphysema (PIE), pneumomediastinum, pneumopericardium, and pneumothorax. Recent studies have shown that the rate of barotrauma-related events is higher in patients with COVID-19 ARDS compared to patients with ARDS secondary to other etiologies. Radiologists should be aware of the imaging features of COVID-19 ARDS as well as the complications of mechanical ventilation. This educational manuscript will review the features of COVID-19 ARDS, discuss imaging of patients on mechanical ventilation, and review the imaging features of complications related to mechanical ventilation, including ventilator-associated lung injuries.

Social Distancing with Portable Chest Radiographs During the COVID-19 Pandemic: Assessment of Radiograph Technique and Image Quality Obtained at 6 Feet and Through Glass.

PURPOSE: To develop a technique that allows portable chest radiography to be performed through the glass door of a patient's room in the emergency department. MATERIALS AND METHODS: A retrospective review of 100 radiographs (50 [mean age 59.4 ± 17.3, range 22-87; 30 women] performed with the modified technique in April 2020, randomized with 50 [mean age 59 ± 21.6, range 19-100; 31 men] using the standard technique was completed by three thoracic radiologists to assess image quality. Radiation exposure estimates to patient and staff were calculated. A survey was created and sent to 32 x-ray technologists to assess their perceptions of the modified technique. Unpaired Ttests were used for numerical data. A P value < .05 was considered statistically significant. RESULTS: The entrance dose for a 50th percentile patient was the same between techniques, measuring 169 µGy. The measured technologist exposure from the modified technique assuming a 50th percentile patient and standing 6 feet to the side of the glass was 0.055 µGy, which was lower than standard technique technologist exposure of 0.088 µGy. Of the 100 portable chest radiographs evaluated by three reviewers, two reviewers rated all images as having diagnostic quality, while the other reviewer believed two of the standard images and one of the modified technique images were non-diagnostic. A total of 81% (26 of 32) of eligible technologists completed the survey. Results showed acceptance of the modified technique with the majority feeling safer and confirming conservation of PPE. Most technologists did not feel the modified technique was more difficult to perform. CONCLUSIONS: The studies acquired with the new technique remained diagnostic, patient radiation doses remained similar, and technologist dose exposure were decreased with modified positioning. Perceptions of the new modified technique by frontline staff were overwhelmingly positive.