Title:Establishing Protocol-based Dose Metrics for Common Abdomen and Pelvis
Computed Tomography Protocols
Volume: 20
Author(s): Entesar Zawam Dalah*, Jamila Salam Alsuwaidi, Reem Salim AlKtebi, Muna Abdellatif Ali AlMulla and Priyank Gupta
Affiliation:
- Department of Head Quarter Diagnostic Imaging, Dubai Health Authority, Dubai, United Arab Emirates
- College of Medicine, Mohammed Bin Rashid University, Dubai, United Arab Emirates
Keywords:
Abdomen and pelvis +C, Triphasic liver, Gastric sleeve, Pancreas phases, SSDE, Effective dose, DRLs.
Abstract:
Background:
The majority of the existing diagnostic reference levels (DRLs) that have been established for computed tomography (CT) are based on various
anatomical locations, such as the head, chest, abdomen, etc. However, DRLs are initiated to improve radiation protection by conducting a
comparison of similar examinations with similar objectives. The aim of this study was to explore the feasibility of establishing dose baselines
based on common CT protocols for patients who underwent enhanced CT abdomen and pelvis exams.
Methods:
Dose length product total (tDLPs), volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), effective dose (E), and scan
acquisition parameters for a total of 216 adult patients, who underwent an enhanced CT abdomen and pelvis exams over a one-year period, were
obtained and retrospectively analyzed. Spearman coefficient and one-way ANOVA tests were used to check significant differences between dose
metrics and the different CT protocols.
Results:
The data exhibited 9 different CT protocols to acquire an enhanced CT abdomen and pelvis exam at our institute. Out of these, 4 were found more
common, i.e., CT protocols were acquired for a minimum of 10 cases. Triphasic liver demonstrated the highest mean and median tDLPs across all
4 CT protocols. Triphasic liver protocol registered the highest E followed by gastric sleeve protocol with a mean of 28.7 and 24.7 mSv,
respectively. Significant differences (p < 0.0001) were found between the tDLPs of anatomical location and the CT protocol.
Conclusion:
Evidently, wide variability exists across CT dose indices and patient dose metrics relying on anatomical-based dose baseline, i.e., DRLs. Patient
dose optimizations require establishing dose baselines based on CT protocols rather than the anatomical location.