Comparative study of radiation dose levels in automatic and manual slice thickness selection in contrast enhanced computed tomography of the abdomen

Abstract

Purpose: To compare the radiation dose in automatic and manual slice thickness selection in Contrast Enhanced Computed Tomography (CECT) Abdomen. Material and Methods: In the department of Radiodiagnosis and Medical Imaging, this prospective study involved 52 participants who were referred for CECT Abdomen scan with a 128-slice CT scanner (GE Revolution EVO). The study involved 26 participants in the automatic slice selection group and another 26 participants in the manual slice thickness based on the participants' cooperation while scanning. Intravascular (IV) contrast material was administered to the patient during a CECT Abdomen scan. After the scan, the dose report was measured based on the slice thickness with the help of DLP to compare the radiation dose between the automatic and manual slice thickness selection methods. Results: IThere was a significant difference in DLP between the automatic slice thickness (AST) and manual slice thickness (MST) groups (p value <0.001). The mean DLP in the automatic slice thickness group was 1152.54 mGy-cm, while in the manual slice thickness group it was notably lower at 802.69 mGy-cm. In the automatic slice thickness and manual slice thickness groups, we observed a statistically significant difference in mean DLP between arterial and venous phases (p value <0.001). Pearson’s correlation was used to compare the correlation among the variables, and we found that, in AST, the arterial and venous phases are closely related, with a correlation of 0.852 (p value <0.0001). In MST, similarly, the arterial and venous phases are strongly related with a correlation of 0.920 (p value <0.0001). Conclusion: This study's findings demonstrated that manual slice thickness was the most effective approach for reducing radiation dose in dual-phase CECT Abdomen scans compared to automatic slice thickness selection.