From the Guidelines
Arterial ultrasound of the lower extremities typically does not include the iliac arteries, as they are difficult to image with conventional ultrasound due to their deep location and overlying bowel gas. The iliac arteries, including the common iliac and internal iliac arteries, are not part of the standard lower extremity arterial ultrasound examination, which focuses on the femoral, popliteal, and tibial vessels 1.
Limitations of Ultrasound for Iliac Arteries
The sensitivity and specificity of duplex ultrasound for diagnosing stenoses in the iliac arteries are decreased due to limitations such as bowel gas, tortuosity, and dense calcification, which can obscure the iliac vessels 1.
Alternative Imaging Modalities
For adequate visualization of the iliac arteries, other imaging modalities such as CT angiography (CTA), MR angiography (MRA), or conventional angiography are generally preferred 1. CTA, in particular, has advantages over ultrasound, including more rapid acquisition and better safety in patients with pacemakers or defibrillators 1.
Clinical Considerations
If iliac artery disease is suspected based on symptoms or abnormal findings in the common femoral artery waveforms, further imaging with CTA or MRA should be considered for complete evaluation of the iliac vessels 1. The choice of imaging modality depends on various factors, including patient characteristics, clinical presentation, and the need for revascularization 1.
Key Points
- Arterial ultrasound of the lower extremities does not typically include the iliac arteries.
- Alternative imaging modalities, such as CTA or MRA, are preferred for visualizing the iliac arteries.
- The choice of imaging modality depends on clinical considerations and patient characteristics.
From the Research
Arterial Ultrasound of the Lower Extremities
- The iliac arteries, including the common iliac and internal iliac arteries, are part of the arterial tree that can be visualized using duplex ultrasound scanning 2, 3, 4.
- Studies have shown that duplex scanning can be used to diagnose iliac and femoropopliteal disease in patients with lower limb arterial disease 2, 3.
- The diagnostic accuracy of duplex ultrasound in detecting occlusion and stenosis in the iliac arteries has been compared to computed tomography angiography (CTA) and digital subtraction angiography (DSA) 4.
- The results of these studies suggest that duplex ultrasound can be a useful tool for diagnosing arterial disease in the lower extremities, including the iliac arteries 2, 3, 4, 5.
- However, the accuracy of duplex ultrasound may vary depending on the specific segment of the arterial tree being examined, with some studies suggesting that CTA may be more accurate for evaluating iliac arterial disease 4.
Specific Studies
- A study published in 1999 found that duplex scanning could adequately visualize the iliac arteries in nearly 80% of patients with lower limb arterial disease 2.
- A study published in 2008 demonstrated the feasibility and safety of intravascular ultrasound-guided endovascular therapy for chronic total occlusion of the iliac and femoropopliteal arteries 6.
- A study published in 1994 found that duplex ultrasonography had a sensitivity of 93% and a specificity of 91% in detecting significant stenoses in the aortoiliac and femoropopliteal arteries 3.
- A study published in 2021 found that duplex ultrasound had a lower accuracy than CTA in evaluating iliac arterial disease, but was still a useful tool for diagnosing hemodynamic stenosis and occlusion of the femoro-popliteal axis 4.
- A study published in 2005 found that the duplex waveform at the common femoral artery could be used as a marker of significant aortoiliac disease, with a positive predictive value of 92% 5.