What are the findings of a Computed Tomography Angiography (CTA) of the aorta and runoff?

From the Guidelines

CT angiography of the aorta and runoff is a highly recommended imaging test for evaluating the aorta and its branches, providing detailed visualization of the arterial system from the chest through the legs in a single examination, with a high sensitivity and specificity of 90% to 100% for detection of stenoses >50% diameter 1. The test is typically recommended for patients with suspected peripheral arterial disease, aortic aneurysm, aortic dissection, or other vascular abnormalities.

• The procedure requires administration of iodinated contrast material through an IV, usually at a rate of 4-5 ml/second for a total of 100-150 ml depending on patient factors.
• Patients should fast for 4-6 hours before the exam but continue to drink clear fluids to maintain hydration.
• Those with impaired kidney function (eGFR < 30 ml/min/1.73m²) may require alternative imaging or preventive measures due to the risk of contrast-induced nephropathy.
• Patients with diabetes taking metformin may need to temporarily discontinue this medication 48 hours before and after the procedure. The scan itself takes only minutes to complete, though the entire appointment may last 30-60 minutes.
• This imaging modality is valuable because it provides comprehensive assessment of vascular pathology with minimal invasiveness compared to conventional angiography.
• Computed tomography angiography has several advantages over other imaging modalities, including short scan time, the ability to obtain a 3-dimensional data set of the entire aorta, wide availability, and low operator dependence 1. However, heavily calcified atheromatous disease can limit the ability to interpret CT images, and dual-energy CTA can reduce blooming and beam-hardening artifact created by heavily calcified atheromatous disease and metallic stents 1.
• The ability to assess the coronary arterial system using CTA has a clear advantage in preoperative planning and may avoid the need for invasive coronary angiography 1.

From the Research

Findings of Computed Tomography Angiography (CTA) of the Aorta and Runoff

• The CTA of the aorta and runoff can provide precise delineation of vascular anatomy and pathology, including stenoses, aneurysms, and dissections 2.
• High-concentration contrast media (HCCM) can be used to obtain high-quality CTA images, which can facilitate precise delineation of the residual lumen in vessels affected by stenoses 2.
• CTA can also provide information on the mural constituents of stenoses, including calcification, which can be useful in treatment planning 2.
• The use of CTA in treatment planning for peripheral arterial occlusive disease (PAOD) has been shown to be effective, with CTA providing accurate visualization of atherosclerotic disease and facilitating treatment decisions 3, 4.
• Structured reporting of CTA runoff examinations has been shown to improve clarity, completeness, and clinical relevance of radiology reports, and can facilitate better decision-making for further testing and therapy 5.
• ECG-gated CT angiography of the thoracic aorta can also provide valuable information on coronary artery disease (CAD), including the presence of significant stenosis and the type of plaque responsible for the stenosis 6.

Key Features of CTA of the Aorta and Runoff

• High-quality images of vascular anatomy and pathology
• Precise delineation of stenoses, aneurysms, and dissections
• Information on mural constituents of stenoses, including calcification
• Accurate visualization of atherosclerotic disease
• Facilitation of treatment decisions for PAOD and CAD
• Improved clarity, completeness, and clinical relevance of radiology reports with structured reporting

Clinical Implications

• CTA of the aorta and runoff can provide valuable information for treatment planning and decision-making in patients with PAOD and CAD
• The use of HCCM and structured reporting can improve the quality and usefulness of CTA images and reports
• ECG-gated CT angiography of the thoracic aorta can provide important information on CAD, which can have a significant clinical impact on patient management 6