Development and implementation of optimized chest CT protocol in COVID-19: A clinical audit

Several studies have justified use of chest computed tomography (CT) in diagnosis, evaluation of severity, treatment response, and complications of coronavirus disease 2019 (COVID-19) pneumonia. Increased utilization of CT in patients with known or suspected COVID-19 pneumonia has resulted in concerns of overuse, lack of protocol optimization, and radiation exposure.

The study was conducted to develop and implement optimized protocol for chest CT for reducing radiation dose in adult patients suspected or diagnosed to have COVID-19 infection.

The study was conducted in the department of radiology of a rural tertiary care teaching hospital in western India. Clinical audit was used as a tool to impart and assess the impact of optimized chest CT protocol.

The pre-intervention audit included radiation dosimetry data, number of phases and length of scan of 50 adult patients, undergoing non-contrast chest CT scans in March 2021. A brief educational intervention outlining the parameters of optimized protocol was conducted on April 1, 2021.The post-intervention audit consisted of two cycles for 109 and 67 chest CT scans in the months April and May 2021.

The optimized protocol was found clinically adequate with a good inter-rater reliability. The compliance to the optimized protocol was weak in audit cycle 2, which improved significantly in audit cycle 3 after reinforcement. The mean (SD) per scan Computed Tomography Dose Index-Volume (CTDI-vol) reduced significantly across audit cycles [22.06 (12. 31) Vs. 10.58 (7.58) Vs. 4.51 (2.90) milli Gray, respectively, P < 0.001]. Similar findings were noted for Dose Length Product (DLP).

Clinical audit of chest CT protocol and resultant radiation doses provided adequate feedback for dose optimization. A simple educational intervention helped achieve dose optimization.