# Evaluating Radiation Exposures and Establishments of National Diagnostic Reference Levels for Patients Undergoing Chest Computed Tomography Examinations in Ethiopia

## TL;DR

This study establishes national diagnostic reference levels for radiation doses in chest CT scans in Ethiopia, comparing them to international standards.

## Contribution

The study provides Ethiopia-specific diagnostic reference levels for chest CT radiation doses, offering a benchmark for optimizing patient safety.

## Key findings

- The calculated DLP and CTDI volume third quartile values for adult chest CT in Ethiopia are 512.9 mGy cm and 10.165 mGy.
- Ethiopia's DRLs are intermediate compared to other African and non-African countries, suggesting room for optimization.
- Scan parameters and exposure control differences may explain dose efficiency variations between countries.

## Abstract

Computed tomography is invaluable for both diagnostic and therapeutic purposes. The common challenge is using an optimized CT technique to produce qualified images while giving patients the least amount of radiation possible. The objective of the study was to determine the national DRL values for adult patients undergoing chest computed tomography examination in Ethiopia. This was a retrospective cross-sectional study conducted in twenty three (23) different CT scan facilities on 801 patients who underwent chest computed tomography examinations in Ethiopia, in which participants were recruited by systematic random sampling. Data processing in this study was carried out with a quantitative analysis technique, namely descriptive statistics. The study variables were CTDI volume and dose length product (DLP) for the radiation doses for chest CT examinations. The age range for all adult patients was above 15 years old. Their body weights were in the range of 40–80 kg. The third quartile of the distributions of the median values of these variables was used to establish chest national diagnostic reference levels. The national DRL was compared with DRLs of other countries. Microsoft Excel form and SPSS software version 26 were used to collect and analyze survey data. A total of 801 patients were examined with an average age of 48.96 years. The patients were examined with their radiological department protocol using multislice CT (MSCT) from different manufacturers. For adult chest computed tomography examinations, the calculated dose length product and computed tomography dose index third quartile values that were used as national diagnostic reference levels were 512.9 mGy cm and 10.165 mGy, respectively.Even though the computed tomography dose index volume of the current study is less than that of all African and non-African countries selected for comparison, the proposed national DLP of the current study values were intermediate and substantially higher than those reported in similar studies from African and non-African countries, respectively. It is plausible to believe that the number of sequences, scan parameters, and automatic exposure control all contribute to better optimization and increased scanner dose efficiency for non-African countries, which is the cause of this discrepancy.