Optimising Urinary Tract CT Scans for Renal Colic: Enhancing Efficiency and Reducing Radiation

Area of Science:

• Radiology
• Medical Imaging
• Radiation Safety

Background:

• Computed tomography (CT) scans for suspected renal colic often exceed national overscan guidelines.
• Unnecessary radiation exposure poses risks, including carcinogenesis.
• A local audit identified suboptimal overscan in the majority of urinary tract CT scans.

Purpose of the Study:

• To reduce unnecessary radiation exposure in a radiology department.
• To design and implement a radiology pathway for suspected renal colic.
• To improve adherence to national overscan criteria for urinary tract CT scans.

Main Methods:

• Retrospective, observational, single-centre study at Basildon & Thurrock University Hospital.
• Reviewed 101 chronological CT scans for suspected renal colic across two audit cycles (Jan-Aug 2025).
• Interventions included a vetting note recommending the T11 vertebra as the upper scan border and a radiographer poster highlighting scan borders.

Main Results:

• Initial audit showed only 36% of scans met overscan criteria; mean overscan DLP was 28.21 mGy·cm.
• Post-intervention, 70.6% of scans met <10% overscan criteria; mean overscan DLP reduced to 16.21 mGy·cm.
• Average excess radiation exposure decreased by 42.6%, and compliance with T11 border positioning increased from 28% to 56.9%.

Conclusions:

• Interventions successfully doubled adherence to national standards within four months.
• Significant reduction in average ionizing radiation exposure lowers carcinogenesis risk.
• Low-fidelity, reproducible interventions encourage national adoption for improved radiation safety in CT imaging.