Radiological evaluation
Computed Tomography images were reretrospectively re-evaluated by 3 radiologists. Typical and atypical chest CT findings related to Covid 19 pneumonia were evaluated separately by each radiologist blinded to the previously written reports. Multifocal ground glass opacities (GGO), consolidation, GGO with superimposed consolidation, consolidation predominant pattern, crazy paving pattern, and melted sugar sign were considered as typical; pleural and/or pericardial effusion, cavity, pulmonary nodule, nodular pattern, lymphadenopathy, peribronchovascular distribution, halo and/or reverse halo sign, three-in-bud sign, bronchiectasis, airway secretions, pulmonary emphysema, pulmonary fibrosis, isolated pleural thickening, and pneumothorax were considered as atypical findings for covid pneumonia.(6) Patients were categorised as “normal”, “typical for covid”, “atypical for covid” and “not covid” similarly with the previous structured reports. Afterwards, parenchymal involvement ratios were visually defined for “typical for covid” and “atypical for covid” groups; <25%, 26-50%, 51-75%, and 76-100%. In case of a conflict between evaluations, the decision was made with the consensus of three radiologists. In addition to this re-evaluation, a forth radiologist searched for preliminary reports, final reports and radiology consultation notes of these patients. The point of this thoughtful research is to find out the very first on-call radiologist’s comment on CT images.
Results of the re-evaluation were compared with previously written reports and also with PCR test results. By this way, the diagnostic accuracy of CT reports was aimed to be determined throughout the whole process from the first stage of the epidemic to the present.