Doses from cervical spine computed tomography (CT) examinations in the UK

Area of Science:

• Medical Imaging
• Radiological Physics
• Radiation Protection

Background:

• Cervical spine CT examinations are common diagnostic procedures.
• Accurate patient dose assessment is crucial for radiation safety.
• Previous national diagnostic reference levels (DRLs) may not reflect current practices.

Purpose of the Study:

• To review current patient doses for cervical spine CT examinations in the UK.
• To compare findings with existing national DRLs.
• To propose updated DRLs for cervical spine CT.

Main Methods:

• A data collection form was distributed to medical physicists and radiographers.
• Information on CT scanners, exposure protocols, and patient dose indices was gathered.
• Data were collected from 73 CT scanners across the UK.

Main Results:

• 97% of scanners utilized automatic exposure control; 60% employed iterative reconstruction.
• The average CT dose index (CTDIvol) was 16.7 mGy (range 3.5–39.7 mGy).
• The average dose-length product (DLP) was 379 mGy cm (range 87–1030 mGy cm) for a 32 cm phantom.

Conclusions:

• The study identified higher patient doses (CTDIvol: 20 mGy, DLP: 440 mGy cm) than previous surveys.
• Existing national DRLs for cervical spine CT require amendment.
• Updated DRLs, standardized to a 32 cm phantom, are proposed.