E1536. Imaging Approach to COVID-19:
Radiological Findings, Lexicon, and COVID-RADS
University of Southern California
Reverse transcriptase polymerase chain reaction (RT-PCR) with a high specificity, is now the confirmatory and reference standard for the diagnosis of COVID-19. However, the variable sensitivity of RT-PCR and its lengthy turnaround time (24–48 h) emphasizes the need for a complementary diagnostic approach. Computed tomography (CT) has been playing a key role in the diagnosis, management, and follow-up of patients with COVID-19. To describe imaging features of COVID-19, we went over 37 published studies, reevaluated the diagnostic features of COVID-19 in the chest CT scan of 3647 patients, and summarized typical, atypical, and temporal findings. We also ventured into a deep comparison of COVID-19 and other viral pneumonias, especially H1N1, looking for similarities and differences in imaging findings. We extracted a list of descriptive terms of imaging findings in COVID-19 and mapped them into the terminology that is commonly used in imaging literature. By this approach (which is recently published), we composed a comprehensive lexicon that can be used for documentation and reporting of typical and atypical imaging findings in COVID-19 patients.
Educational Goals / Teaching Points
Our scrutiny of CT scan features of COVID-19 in published studies shows a substantial inconsistency in lexicon. The variability in the description of imaging findings can be confusing for healthcare providers. In this exhibit, educational goals are to:
propose an organized system of reporting that would simplify the interpretation of imaging examinations, serve as a structure for consistent generation of recommendations, and could lead to a higher quality of patient care; introduce COVID-19 imaging reporting and data system (COVID-RADS), which is a grading system for CT findings with five categories - each grade corresponds to a low, moderate, or high level of suspicion for pulmonary COVID-19 involvement; and delineate all typical and atypical imaging findings of COVID-19 and introduce a common lexicon that will help distinguish it from other common viral infections, particularly H1N1 influenza, which their co-incidence could become a serious predicament for health providers
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The sensitivity of CT scan in diagnosis of COVID-19 is up to 97%. The diagnostic value of this modality has been clearly shown in clinically suspicious cases with inconclusive laboratory test results, as well as asymptomatic individuals with known exposure. In many healthcare settings (developing countries), CT scan may be more available due to a shortage of RT-PCR kits. In many COVID patients with laboratory confirmed tests, CT scan yields a typical pattern of multifocal bilateral ground glass opacities (GGOs) with a peripheral and posterior distribution and later superimposition of consolidations.
This exhibit will hopefully improve the communication of findings with other healthcare providers, facilitate the diagnosis and management of COVID-19 patients, and differentiate it from other viral pneumonias, particularly H1N1.