Term
| LE Color Duplex Imaging Goals |
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Definition
| Id exact site of disease.Differentiate stenosis vs occlusion. Define length of occlusion. Id aneurysms. Id & guide treatment of pseudoaneurysms. Id AVF, AVM, and venous malformations. Adjunct to physiologic testing. Intraoperative & post-op evaluation of bypass grafts. |
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Term
| LE Color Duplex Technique |
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Definition
Patient supine (for CFA), head slightly elevated for patient comfort.
Use 5 – 9 MHz transducer with 3.5 – 4 MHz Doppler. Start at inguinal crease.
Get close to the leg. |
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Term
| LE Doppler Waveform Sites |
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Definition
| Scan whole vessel. Sample from: EIA,CFA,SFA,PFA,POPA. Measure PSV. |
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Term
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Definition
| >0.14s (>144ms) is abnormal. |
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Term
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Definition
% Stenosis Peak Vel Velocity Ratio
Normal <150 <1.5:1
30-49 150-200 1.5:1 - 2:1
50-75 201-400 2:1 - 4:1
>75 >400 >4:1
Occlusion No Color Saturation |
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Term
|
Definition
Nothing with Color & Spectral Doppler.
Id collateral run-off. Id distal reconstitution of collateral. |
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Term
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Definition
| Major arteries lie right next to major deep veins, use the veins as landmarks. Long-standing occluded vessels are often contracted & difficult to id. Use length of linear transducer face ( 4 cm) as a “rough” ruler to measure occlusion distances that are longer than image field of view. Blood can flow in either direction in an artery, bc no valves. |
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Term
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Definition
Begin longitudinal color Doppler scan of PTA at medial malleolus & follow artery proximally along the course of the tibia.
Use a low color PRF as flow may be slow. |
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Term
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Definition
≥ 3 cm: Abdominal Aorta (>5cm=Surgery)
≥ 2 cm: Iliac Artery
≥ 1 cm: Popliteal Artery |
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Term
| Aneurysm Diagnostic Method |
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Definition
| In Transverse: Measure Ant.-Post. & lateral distance. Measure residual lumen. In Sagital: Measure length. Id if thrombus is present. Id if artery is occluded or patent. Measure diameter proximal & distal. |
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Term
| Popliteal Artery Aneurysm |
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Definition
Atherosclerotic? Risks: Thrombosis,
Emboli(Greatest Risk), Venous/Nerve Compression, Rupture. More frequent in men. If thrombosed:40-75% amputation rate. Usually bilateral (50-70%).
Likelihood of AAA is 43 %. |
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Term
| Popliteal Symptoms Aneurysm |
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Definition
Claudication. Rest Pain. Limb Ischemia.
Blue Toe. Nerve Compression/Pain. |
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Term
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Definition
| High-pressure extravasation of blood into surrounding tissue. No arterial wall encapsulating aneurysm. “To & Fro” flow in aneurysm neck. |
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Term
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Definition
Percutaneous arterial catheterization.
Penetrating trauma.
Graft anastomosis “blowout”. |
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Term
| Pseudoaneurysm Diagnostic Method |
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Definition
Id “neck” of aneurysm. To & fro flow?
Is artery torn? Long “neck” = no tear.
Is there extrinsic compression of artery by P-aneurysm? Measure size. Check vein for fistula flow. |
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Term
|
Definition
60% thrombose spontaneously.
Surgical repair. Manual compression with CDI. Thrombin injection. |
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Term
| Pseudoaneurysm Compression Repair. |
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Definition
Discontinue heparin 2 hrs prior, resume 4 hours post. Intravenous analgesic (narcotic). 15-20 min compressions. Monitor distal perfusion.
Bed rest for 6 hours post. |
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Term
|
Definition
Orient transducer longitudinal (parallel) to needle.
Turn off color when inserting needle. Do not let needle into artery. |
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Term
| Aorta and Iliacs; Duplex Disadvantages |
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Definition
| Time consuming and difficult. Color flash artifact. Depth. Bowel gas. |
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Term
| Aorta and Iliacs; Patient Preparation |
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Definition
| NPO for 8 hrs prior. Perform exam in am. Patients may take clear liquids, medications. Diabetics; appropriate nourishment. |
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Term
| Aorta and Iliacs; Imaging Technique |
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Definition
Use a 2.5 - 3.5 MHz transducer.
Apply appropriate transducer pressure in abdomen to displace bowel gas.
Look for aneurysms. |
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