RadteraUltrasound Abdominal Aorta (AAA Screen)
USNo contrastVascular
Indications
- AAA screening (e.g., men 65-75 with smoking history)
- Pulsatile abdominal mass
- Surveillance of known aneurysm
- Abdominal/back pain in at-risk patient
Patient prep
- NPO 6-8 hours preferred to reduce bowel gas (screening can be done non-fasting if needed)
- Supine; decubitus to use bowel-gas-free windows
Contrast
None / non-contrast
Technique
- Curvilinear 2-5 MHz transducer
- Image aorta from diaphragm to bifurcation in transverse and longitudinal
- Measure outer-wall-to-outer-wall AP diameter perpendicular to the lumen
- Color Doppler if dissection/thrombus or iliac involvement suspected
Series / Sequences
| # | Series / Sequence | Plane | Notes |
|---|---|---|---|
| 1 | Proximal aorta (suprarenal/at diaphragm) | Transverse and long | Outer-to-outer AP diameter |
| 2 | Mid aorta (juxtarenal) | Transverse and long | AP diameter |
| 3 | Distal aorta (above bifurcation) | Transverse and long | AP diameter; mural thrombus |
| 4 | Aortic bifurcation / common iliac arteries | Transverse | Iliac diameters if dilated (>1.5 cm) |
Key points
- AAA defined as aortic diameter >=3.0 cm (outer-to-outer AP)
- Always measure outer wall to outer wall perpendicular to the long axis to avoid underestimation
- Document maximal diameter and presence of mural thrombus; include iliacs
- Surveillance intervals per size; rapid expansion or symptoms warrant urgent evaluation
References
• AIUM Practice Parameter for the Performance of Diagnostic and Screening Ultrasound Examinations of the Abdominal Aorta in Adults
• ACR Appropriateness Criteria: Pulsatile Abdominal Mass — Suspected AAA
• Radiopaedia: Abdominal aortic aneurysm link
• ACR Appropriateness Criteria: Pulsatile Abdominal Mass — Suspected AAA
• Radiopaedia: Abdominal aortic aneurysm link
Source: Researched — verify against your institution
Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.