COMPARATIVE STUDY OF RADIATION DOSE LEVELS IN AUTOMATIC AND MANUAL SLICE THICKNESS SELECTION IN CONTRAST ENHANCED COMPUTED TOMOGRAPHY 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 are referred for CECT Abdomen scan with 128 slice CT scanner (GE Revolution EVO). The study involved 26 participants in automatic slice selection group and another 26 participants in manual slice thickness based on the participants co-operation while scanning. Intravascular (IV) contrast material was administrated to the patient during a CECT Abdomen scan. After the scan, dose report was measured based on the slice thickness with the help of DLP to compare the radiation dose between automatic and manual slice thickness selection method.

RESULTS

There 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 manual slice thickness group it was notably lower at 802.69 mGy-cm. In automatic slice thickness and manual slice thickness group, we observed statistically significant difference in mean DLP between arterial and venous phase (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 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 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.