CT Aorta — Acute Aortic Syndrome
CTImmediate
ED
All imaging requests must be justified by an IR(ME)R practitioner (radiologist or radiographer)Required Assessment Tools
OPTIONAL
Aortic Dissection Detection Risk Score (ADD-RS)
Clinical pre-test probability tool for aortic dissection
≥1 = imaging may be warranted; ≥2 = immediate CTA indicated
Indications
Immediate— ANY of the following
- Suspected aortic dissection (Type A or Type B)
- Suspected intramural haematoma
- Suspected penetrating aortic ulcer
- Suspected symptomatic or ruptured AAA — bedside USS first, then CTANICE NG156 Rec 1.2.1
- Suspected traumatic aortic injury (blunt thoracic trauma, widened mediastinum, deceleration)
Notes
Information
ADD-RS ≥1 = imaging may be warranted (consider CTA); ADD-RS ≥2 = high pre-test probability — immediate CTA indicated
Information
ECG-gated CTA preferred for ascending aorta. Sensitivity approaching 100%.
Warning
Haemodynamically unstable ruptured AAA — directly to CT if stable enough, otherwise theatre
Information
Protocol title reflects all three AAS components per RCR/RCEM 2024/2025
RCR/RCEMRadiation Dose
CTA aorta effective dose ~10–15 mSv (ECG-gated)
Change Log
v1.02026-03-05Initial publication
v2.02026-03-08ADD-RS scoring tool added. RCR/RCEM 2024/2025 guidance confirmed.