Correlation of Indeterminate Lesions of COVID-19 Pneumonia Detected on Computed Tomography with RT-PCR Results

The typical findings of COVID-19 pneumonia include multilobar groundglass opacities and consolidation areas observed predominantly in the basal and peripheral parts of both lungs in computed tomography.

The current study aimed to correlate indeterminate lesions of COVID-19 pneumonia detected on computed tomography with the results of the reverse transcription-polymerase chain reaction (RT-PCR) test.

Patients with high-resolution computed tomography images that were reported to contain indeterminate lesions in terms of COVID-19 pneumonia were included retrospectively in the study. The lesions were categorized and the patterns were classified. The RT-PCR-positive and the RTPCR- negative patients were compared. P<0.05 was accepted as the statistical significance limit.

The RT-PCR-positive patients exhibited a higher rate of peripheral lesions. Limited consolidation areas were not detected in the RT-PCR-positive patients. In the RT-PCR-negative patients, the rates of acinar nodules and the tree-in-bud pattern were significantly higher. The RTPCR- negative patients had higher nodular contour features and lesion coalescence. In the subgroup consisting of lesions with ground-glass opacities and/or ground-glass opacity around the nodule, the rate of nodular contour positivity was significantly higher in the RT-PCR- positive patients.

COVID-19 pneumonia should be suspected when peripheral indeterminate lesions are detected. When indeterminate lesions, such as tree-in-bud pattern, acinar nodules and limited consolidation area are detected, alternative diagnoses should be considered first, even if there are ground glass opacities accompanying these lesions.