Sonographers should follow a standard imaging protocol. A complete evaluation includes B- mode, spectral Doppler analysis, and color Doppler imaging of all accessible portions of the upper extremity arteries. Bilateral evaluations are essential for a complete evaluation; however, studies may be unilateral or limited based on laboratory-specific protocols.

During each examination, the sonographer or examiner should:

• Observe the sonographic characteristics of normal and abnormal tissues, structures, and blood flow to allow the necessary adjustment for optimizing 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 are provided to the physician to direct patient management and render a final diagnosis.

If not contraindicated, bilateral systolic brachial pressures should be documented to assess symmetry.

B-Mode and color Doppler imaging of the upper extremity arteries should be performed in a longitudinal plane. Transverse imaging may be helpful. Longitudinal grayscale and color Doppler images should be documented for each normal arterial segment and in areas of stenosis, previous interventions, or other abnormalities. Color Doppler is used to localize areas of flow disturbance and stenosis. Power Doppler is useful to confirm possible vessel occlusion or low flow states.

Longitudinal B-mode and/or color Doppler images should include the following:

• Subclavian artery
• Axillary artery
• Brachial artery
• Radial and ulnar arteries
• Innominate artery (when indicated by facility protocol or based on findings)
• Areas of previous intervention (angioplasty, stenting)
• Bypass graft(s), when present, including anastomoses

Doppler spectral analysis is used to quantify disease severity. Spectral Doppler waveforms should be obtained in a longitudinal plane at an angle of 60° and parallel to the direction of the blood flow/vessel walls. Maintain Doppler angles between 45° to 60° whenever possible. Avoid angles greater than 60°.

Peak systolic velocities should be documented for each normal arterial segment and in areas of stenosis, previous intervention or other abnormality. Spectral Doppler waveforms and velocity measurements should be obtained 1 to 4 cm proximal to, within and distal to the suspected stenosis, obstruction, or in areas of previous intervention.

Spectral Doppler waveforms and velocity measures should include:

• Subclavian artery
• Axillary artery
• Brachial artery
• Radial and Ulnar arteries
• Innominate artery (when indicated by facility protocol or based on findings)
• Areas of previous intervention (angioplasty, stenting)
• Bypass graft(s) when present, should include the following:
  • Inflow and outflow arteries
  • Proximal and distal anastomosis
  • Proximal, mid, and distal graft

Abnormalities requiring further examination and additional images when present:

• Areas of stenosis: Pre-stenosis, at stenotic site, and post-stenotic turbulence. Peak systolic velocity ratio (VR) is used to determine if the lesion is hemodynamically significant. The PSV ratio is obtained by taking the PSV at the area of stenosis and dividing by the PSV in the normal segment proximal to the stenosis.
• Areas of an aneurysm: Obtain outer wall to outer wall diameter measurements and spectral Doppler velocities proximal to, within and distal to the aneurysm. Subclavian artery aneurysm may be difficult to obtain due to its proximity to the clavicle. Document when mural thrombus is present.
• In the presence of a brachial pressure difference greater than 20 mmHg: the ipsilateral vertebral artery should be evaluated for direction of flow when vertebral-to-subclavian steal is suspected.
• In the presence of other surgical interventions (angioplasty or stents): evaluate the proximal inflow artery, endovascular segment and distal artery.