RadteraCTA Thoracic Aorta (Aneurysm / Dissection)
CTA+ ContrastVascular
Indications
- Suspected acute aortic syndrome: dissection, intramural hematoma, penetrating atherosclerotic ulcer
- Thoracic aortic aneurysm evaluation and surveillance
- Traumatic aortic injury
- Pre-/post-operative or post-TEVAR endoleak assessment
- Suspected aortic rupture
Patient prep
- Screen eGFR/contrast allergy; premedicate if indicated
- Large-bore IV (18-20 G) for high flow rate
- ECG leads if gated acquisition; supine, arms up
- Breath-hold at suspended inspiration
Contrast
Agentiodinated, high concentration (e.g. iohexol 350 or iopamidol 370)
RouteIV
Dose≈80-120 mL at 4-5 mL/s with saline flush
TimingBolus tracking ROI in ascending/descending aorta, trigger ~100-150 HU, arterial phase; non-contrast series first for IMH/hemorrhage; delayed phase for endoleak/dissection extent as needed
Technique
- Supine, arms up; coverage from thoracic inlet through diaphragm (extend through groin/abdomen+pelvis if dissection to evaluate full aorta and run-off)
- ECG-GATING (prospective or retrospective) reduces aortic root/ascending motion artifact — important to avoid pulsation artifact mimicking dissection at the root
- 100-120 kV (lower kV for iodine conspicuity); mAs per scanner with AEC; iterative reconstruction
- Reconstruct thin (0.625-1 mm) source; multiplanar, curved-planar, MIP and 3D VR reformats; centerline measurements
- Non-contrast low-dose series to detect intramural hematoma/high-density crescent and exclude hemorrhage
Series / Sequences
| # | Series / Sequence | Plane | Thickness | Notes |
|---|---|---|---|---|
| 1 | Non-contrast axial | axial | 2.5-3 mm | Detect IMH, hyperdense crescent, hematoma, hardware baseline |
| 2 | Arterial CTA (ECG-gated) | axial | 0.625-1 mm | Thin source; dissection flap, true/false lumen, branch involvement |
| 3 | Multiplanar/curved reformats & 3D | multiplanar | n/a | MIP/VR, centerline diameters for aneurysm sizing |
| 4 | Delayed phase (selective) | axial | 2-3 mm | Endoleak after TEVAR, slow-flow false lumen |
Key points
- ECG-gating is recommended for ascending aorta/root to eliminate pulsation artifact that can mimic a dissection flap
- Always include a non-contrast series for suspected acute aortic syndrome to detect intramural hematoma (hyperattenuating crescent) and acute hemorrhage
- Extend coverage to abdomen/pelvis to map dissection extent, branch-vessel involvement and malperfusion
- Add delayed phase for endoleak surveillance after endovascular repair; report by anatomic landmarks and maximal diameters perpendicular to centerline
References
• ACR–NASCI–SPR Practice Parameter for the Performance and Interpretation of Body CT Angiography
• ACR Appropriateness Criteria: Suspected Acute Aortic Syndrome; Thoracic Aorta Surveillance
• Radiopaedia: CT aorta (protocol) link
• RadioGraphics: CT Angiography of Acute Aortic Syndromes
• ACR Appropriateness Criteria: Suspected Acute Aortic Syndrome; Thoracic Aorta Surveillance
• Radiopaedia: CT aorta (protocol) link
• RadioGraphics: CT Angiography of Acute Aortic Syndromes
Source: Researched — verify against your institution
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Reference template — verify and adapt to your scanner, vendor and institution before clinical use. Not a substitute for clinical judgment.