Redefining “indeterminate” ground glass opacities in SARS-CoV-2

Abstract

Background: Isolated ground glass opacities are often seen in the lungs and these are a diagnostic challenge. There are numerous different causes of ground glass opacities in the lungs. The broad list of etiologies are infectious causes, interstitial disease, alveolar disease, neoplastic, and drug toxicity. In the era of SARS Cov-2, it becomes very difficult to differentiate the ground glass opacities due to inflammatory bronchiolitis and other viral pneumonitis from those which are due to SARS CoV-2. Aims and Objectives: We aim to look for vascular signs seen in association with ground glass opacities which increase our level of confidence to call them ground glass opacities due to SARS-CoV-2 as an etiology. Materials and Methods: We present an observational study on 34 patients who presented with only patchy focal ground glass opacities in the lungs. All these patients were also subjected to nasopharyngeal swab test. The vascular signs seen on CT scan were of help to establish definite diagnosis of SARS-CoV-2 only on the basis of ground glass opacities. Results: Out of 31 patients showing CT scan finding of prominent intralesional vessel, 27 were positive for COVID-19 on reverse transcription-polymerase chain reaction (RT-PCR) test. Four patients showing prominent intralesional vessel on CT scan were negative for COVID-19 infection on RT-PCR test. These four patients who were tested negative on RT-PCR were treated symptomaticaly for inflammatory bronchiolitis. Follow-up CT scan of two such patients were done after 4 days, which showed resolution of the focal ground glass opacities. Conclusion: The parenchymal imaging findings of SARS-Cov-2 are well described as ground glass opacities associated with septal thickening and consolidation. However, in some cases, only few focal isolated ground glass opacities are seen without any other typical features. In such cases, the vascular signs are of help to increase our level of diagnostic confidence.