Lower-Extremity CT Angiography: Inter-Hospital Dose Variability and Protocol Optimization in Sudan

Area of Science:

• Radiology
• Medical Imaging
• Radiation Oncology

Background:

• Lower-extremity CT angiography (CTA) is crucial for diagnosing peripheral arterial disease.
• Significant radiation exposure is a major concern with CTA procedures.
• Protocol design variability contributes to dose differences even with identical CT scanners.

Purpose of the Study:

• To assess inter-hospital variability in radiation dose for lower-extremity CTA.
• To identify protocol-related factors for dose optimization.
• To evaluate dose metrics on identical 64-slice CT scanners.

Main Methods:

• A multicentre retrospective observational study of 74 adult patients.
• Analysis of radiation dose metrics (CTDIvol, DLP) across four hospitals.
• Correlation of dose metrics with acquisition parameters and scan coverage.

Main Results:

• Mean cumulative DLP varied by approximately 1.5-fold across centers (5333.2–7911.6 mGy·cm).
• Non-contrast and contrast-enhanced helical phases were the primary dose contributors.
• Several protocols exceeded diagnostic reference levels; optimization strategies like low-tube-voltage and iterative reconstruction are feasible.

Conclusions:

• Radiation dose in lower-extremity CTA is primarily protocol-dependent.
• Strategies such as selective non-contrast phase omission and low-tube-voltage acquisition can significantly reduce dose.
• Harmonized protocol implementation is essential for consistent dose reduction.