Computed Tomography Angiography

* **Gold standard** for aortic disease, including abdominal aortic aneurysm (AAA), thoracoabdominal aortic aneurysm (TAAA), and thoracic endovascular aortic repair (TEVAR) planning [@aha2022-isselbacher].
* **Technical essentials:** Submillimeter collimation (≤1 mm), multiphasic acquisition (non-contrast, arterial phase with bolus-tracking, delayed phase for endoleak detection), electrocardiogram (ECG)-gating for thoracic aorta when assessing root or ascending segments, standardized contrast delivery (4–6 mL/s) with saline chaser, and iterative reconstruction algorithms to reduce radiation dose.
* **Applications:**
  * AAA and TAAA morphology assessment and access vessel evaluation; see [[Aneurysmal Diseases|Ch. 4]] for measurement standards and repair thresholds [@aha2022-isselbacher].
  * Endovascular aneurysm repair (EVAR) and TEVAR planning and surveillance.
  * Carotid and aortic arch assessment; see [[Cerebrovascular Disease|Ch. 7]] for carotid imaging protocols.
  * Peripheral arterial disease (PAD) mapping [@svs2024-b].
* **Surveillance protocols:** Baseline computed tomography angiography (CTA) at 30 days post-procedure, follow-up at 12 months, then individualized surveillance based on aneurysm sac behavior and endoleak status. Consider duplex ultrasound or contrast-enhanced ultrasound (CEUS) in patients with stable anatomy or renal insufficiency.
* **Limitations:** Ionizing radiation exposure and iodinated contrast risks (nephropathy, allergic reactions).
* **Guidelines:** ESVS AAA (2019),(2024), ESVS carotid (2018), and ACC/AHA aortic (2022) guidelines recommend CTA as a primary planning tool, with aneurysm and post-repair imaging surveillance tailored to patient and device factors [@sun2011] [@esvs2019-aaa][@esvs2024-editors] [@esvs2018-esvs] [@svs2018] [@evar2019] [@aha2022-isselbacher]. The 2024 multi-society PAD guidelines emphasize CTA for anatomic mapping and procedural planning in symptomatic patients [@svs2024-b].