Imaging in the Intensive Care Unit.

Radiology plays an important role in the management of the most seriously ill patients in the hospital. Over the years, continued advances in imaging technology have contributed to an improvement in patient care. However, even with such advances, the portable chest radiograph (CXR) remains one of the most commonly requested radiographic examinations. While they provide valuable information, CXRs remain relatively insensitive at revealing abnormalities and are often nonspecific. Chest computed tomography (CT) can display findings that are occult on CXR and is particularly useful at identifying and characterizing pleural effusions, detecting barotrauma including small pneumothoraces, distinguishing pneumonia from atelectasis, and revealing unsuspected or additional abnormalities which could result in increased morbidity and mortality if left untreated. CT pulmonary angiography is the modality of choice in the evaluation of pulmonary emboli which can complicate the hospital course of the ICU patient. This article will provide guidance for interpretation of CXR and thoracic CT images, discuss some of the invasive devices routinely used, and review the radiologic manifestations of common pathologic disease states encountered in ICU patients. In addition, imaging findings and complications of more specific clinical scenarios in which the incidence has increased in the ICU setting, such as patients who are immunocompromised, have interstitial lung disease, or COVID-19, will also be discussed. Communication between the radiologist and intensivist, particularly on complicated cases, is important to help increase diagnostic accuracy and leads to an improvement in the management of the most critically ill patients.

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.