Comparison of Different Slice Thicknesses on Chest Computed Tomography for Evaluation of COVID-19- Associated Pneumonia.

Objective: To compare the value of chest computed tomography at 1-mm and 5-mm slice thickness in terms of computed tomography severity score and computed tomography evaluation time in the diagnosis of COVID-19.

Material and methods: Sixty-five patients were included in the study group who are reverse-transcription polymerase chain reaction-positive for COVID-19 and had chest computed tomography. The 1 mm and 5 mm reconstructed images were evaluated in 2 different sessions with 4-week intervals by 2 certificated general radiologists. The presence of COVID-19-related findings, COVID-19 final category, and evaluation time were recorded. Thin and thick slices were compared for these variables and inter-reader reliability calculated with the Statistical Package for the Social Sciences (SPSS) for Windows.

Results: There was no significant difference between the COVID-19-related findings on thorax computed tomography between 1-mm and 5-mm slices except crazy paving appearance, microvascular enlargement, and septal thickening. The frequency of the final categories of computed tomography results was consistent between the thick and thin slices. The computed tomography assessment time was significantly lower in 5 mm slices. The inter-reader reproducibility analysis results demonstrated good and excellent reproducibility of measurements between readers for both slice thicknesses.

Conclusion: It was found that 5-mm reconstruction thickness of chest computed tomography can be employed for the initial detection of COVID-19-related findings and the final diagnostic category-related COVID-19 rather than 1-mm slices with a faster availability of results which can be beneficial on pandemic hospitals.