Inter‐Observer Agreement between Low‐Dose and Standard‐Dose CT with Soft and Sharp Convolution Kernels in COVID‐19 Pneumonia

Abstract

Computed tomography (CT) has been an essential diagnostic tool during the COVID‐19 pandemic. The study aimed to develop an optimal CT protocol in terms of safety and reliability. For this, we assessed the inter‐observer agreement between CT and low‐dose CT (LDCT) with soft and sharp kernels using a semi‐quantitative severity scale in a prospective study (Moscow, Russia). Two consecutive scans with CT and LDCT were performed in a single visit. Reading was performed by ten radiologists with 3‐25 years’ experience. The study included 230 patients, and statistical analysis showed LDCT with a sharp kernel as the most reliable protocol (percentage agreement 74.35 ± 43.77%), but its advantage was marginal. There was no significant correlation between radiologists’ experience and average percentage agreement for all four evaluated protocols. Regarding the radiation exposure, CTDIvol was 3.6 ± 0.64 times lower for LDCT. In conclusion, CT and LDCT with soft and sharp reconstructions are equally reliable for COVID‐19 reporting using the “CT 0‐4” scale. The LDCT protocol allows for a significant decrease in radiation exposure but may be restricted by body mass index.