Sonographers should follow a standard imaging protocol. A complete evaluation includes B-mode imaging, spectral Doppler analysis, and color Doppler imaging of all accessible portions of the abdominal aorta and iliac arteries.

Throughout each examination, the sonographer or examiner should:

• Observe sonographic characteristics of normal and abnormal tissues, structures, and blood flow, allowing necessary adjustments to optimize exam quality.
• Assess and monitor the patient’s physical and mental status, allowing modifications to the procedure plan according to the patient’s clinical status.
• Analyze sonographic findings to ensure that sufficient data is provided to the physician to direct patient management and render a final diagnosis.
• Accurately annotate B-mode, color and spectral Doppler images.

Abdominal Aortic Aneurysm Evaluation

Sonographer should follow a standard exam protocol for abdominal aortic aneurysm evaluation.

• Utilize B-mode imaging to examine the aorta beginning at the diaphragm and progressing to the iliac arteries bilaterally to the groins.
• Longitudinal grayscale images should include:
  • Proximal aorta
  • Mid aorta
  • Distal aorta
• Additional images proximal and distal to an aneurysmal segment should be included
  • Transverse aortic and iliac artery diameters by measuring outer wall to outer wall at region of greatest dilation at these specific locations
    • Proximal aorta
    • Mid aorta
    • Distal aorta
    • Common iliac arteries at the bifurcation
• Examine the length of the iliac artery bilaterally and document any abnormalities.
• Identify the internal iliac arteries and measure size, if possible.
• Use color duplex to demonstrate the lumen and to confirm patency of the abdominal aorta and iliac segments.
• Document the presence of abnormalities such as, but not limited to:
  • Thrombus, residual lumen
  • Dissection, flaps
  • Pseudoaneurysm
  • Arterial wall defects
  • Focal stenosis and/or occlusion

Document stenosis and sites of pathology using angle corrected pulsed wave Doppler by recording spectral Doppler waveforms with the angle cursor adjusted parallel to the vessel wall. Interrogate the following locations:

• Proximal abdominal aorta at or proximal to renal artery
• Mid aorta
• Distal aorta
• Right and left common iliac arteries
• Right and left external iliac arteries
• Additionally, if identified, record spectral waveforms from the internal iliac vessel.

Abdominal Aortoiliac Duplex Evaluation for Occlusive Disease

Follow a standard exam protocol for evaluation of abdominal aortoiliac occlusive disease.

• Use B-Mode imaging to examine the native aorta with B-mode imaging from the level of the diaphragm through the length of the aorta and through the length of the iliac arteries bilaterally to the groin.
• Document aortic and iliac artery transverse diameters by measuring outer wall to outer wall
• Document the presence, extent and surface characteristics of plaque, dissection and thrombus
• Examine the length of the iliac artery bilaterally and document any anatomic or pathologic abnormalities
• Use color and pulsed wave Doppler information to:
  • Document patency of the aorta and its branches
  • Record representative images confirming patency, residual lumen and wall defects
• Confirm abnormalities including but not limited to:
  • Presence of plaque
  • Thrombus
  • Dissections
  • Pseudoaneurysm
  • True aneurysms
  • Arterial wall defects,
  • Stenosis and/or occlusion

Record pulse wave velocity proximal to, at site of and distal to region of stenosis using a Doppler angle of (45 to 60 degrees, 60 degrees is optimal with the cursor aligned parallel to vessel wall).

Document branch artery anatomy and patency (celiac, superior mesenteric, inferior mesenteric, renal and hypogastric arteries) per lab protocol.

General Considerations:

• Color Doppler and pulsed wave spectral Doppler are required for the assessment of the aorta and its branches. Color Doppler is necessary for identification of accessory renal arteries, inferior mesenteric, and lumbar arteries.
• Additionally, color Doppler is useful in differentiating vascular from nonvascular structures; provides greater definition of the residual lumen; enhances sensitivity in detecting low-velocity flow states and allows the ability to readily visualize direction of flow.

Endovascular Aortoiliac Stent Graft Evaluation

Follow a standard exam protocol for each endovascular stent graft evaluation.

• Use B-Mode imaging to:
  • Evaluate and document the location and position of the stent fixation sites to evaluate stent for apposition to the wall and/or endoleak.
  • Record the maximum cross-sectional aneurysm diameter(s) to assess for aneurysm enlargement.
  • Ensure proper alignment of the cross-sectional image to the axis and orientation of the longitudinal image to reduce foreshortening or elongating the true transverse view.
  • Examine the residual aneurysmal sac for areas of echolucency or motion/pulsation in the excluded lumen that may represent endoleak.
• Record color Doppler images of renal and visceral arteries to demonstrate patency, stenosis or occlusion.
• Record spectral Doppler waveforms from the body of the graft and each limb of the stent graft and evaluate for any evidence of twisting, kinking, or deformity of the graft.
• Use color and spectral Doppler to assess the attachment/fixation sites with attention to the detection of any flow outside the lumen of the graft.
• Obtain transverse color Doppler images of the aneurysm sac demonstrating color filling of stent graft limbs to demonstrate patency.
  • Examine the aneurysm sac in both sagittal and transverse planes to detect flow that may represent endoleak.
• Equipment settings for color Doppler to detect endoleak should be altered from general arterial settings to low flow settings
• Special attention should be directed to hypoechoic areas within the aneurysm sac that demonstrate the presence of color Doppler to confirm flow with pulsed wave Doppler.
• Record color Doppler image of patent aneurysm sac branches (i.e. lumbar, inferior mesenteric artery, internal iliac artery) and document flow direction.
• Record spectral Doppler waveforms from any region of extra graft flow detected within the aneurysmal sac and from aortic side-branches (document direction of flow and the source of flow and characteristics of the waveform: low resistance, high resistance or to-fro).
• Any complications following endograft placement (e.g., stenosis, occlusion, hematoma, arteriovenous fistula, intimal flaps, dissection or pseudoaneurysm, at access sites) should be thoroughly documented.
• When intervention (PTA with or without stent) has occurred for occlusive disease, the length of treated area should be carefully assessed, particularly if stent(s) have been placed. The stent should be evaluated for alignment, full deployment and relationship to the vessel wall. The Doppler cursor should be carefully “walked” throughout the entire length of the stent(s).

General considerations:

• Color Doppler imaging settings should be optimized to demonstrate and detect low flow aneurysmal sac endoleaks. The color scale should be decreased as low as possible and low filter settings should be utilized.
• Color Doppler imaging is a useful component as it assists with locating endoleaks, assists with vessel localization and aids in following vessels.