click below
click below
Normal Size Small Size show me how
Vascular sonography
Test 3 Lower Extremity venous Pathology- DVT
Question | Answer |
---|---|
Echogenic material is visualized where? | Within the vein lumen |
What type of material prevents complete compression of vein walls? | Echogenic material |
In cases where intraluminal echoes are difficult to visualize, what can used to determine the presence of a thrombus? | Increased transducer compression to deform artery can help determine the presence of a thrombus |
Duplex imaging cannot only detect presence of a thrombus but also what? | The age of a thrombus, which determines the treatment options |
What are the characteristic of acute thrombus? | Lightly echogenic or hypoechoic thrombus, Poorly attached to vessel wall, Often in center of lumen, Spongy texture of thrombus, Dilated vein, "Rouleaux" flow |
What is Rouleaux flow? | Slow flow, moves with respirations |
What does Rouleaux flow suggest? | Proximal obstruction |
Acute thrombosis is what? | The newly formed thrombus is the fluid and solid contents captured in the thrombin net |
What type of thrombus can be invisible on ultrasound? | Acute thrombosis |
What type of thrombus is poorly attached making it more likely to embolize and cause PE? | Acute thrombosis |
What type of thrombus is emergent in the deep system? | Acute thrombosis |
Thrombus should be considered _______ until proven otherwise? | Acute |
When does an acute thrombus typically turn subacute? | typically at 4-12 weeks |
What may determine acute vs. subacute thrombus? | D-dimer |
What does a positive D-dimer indicate? | Indicates significant thrombus formation |
What does a negative D-dimer indicate? | Indicates acute process is not occurring |
What are the characteristics of Chronic Thrombus? | Brightly echogenic, Well-attached to vessel wall, Rigid texture of thrombus, Contracted vein (only if obstructed), Vessel retracts with aging thrombus, Large collateral, Several months old |
What is capable of dissolving Venous Thrombosis? | The Thrombolytic system |
How long does it take for a thrombus to become chronic? | Several months |
Chronically thrombosed veins may be difficult to differentiate from what? | Surrounding tissue |
Does chronic thrombus always obstruct the vein? | NO, not always |
A chronic thromus may appear as a what within the vein? | A thin scar |
What are phleboliths? | Calcifications |
Absence of color flow and spectral waveform will be seen in what? | Completely thrombosed veins |
If there is no augmentation with distal compression what does that mean? | Mean that the obstruction is located between the transducer and the site of distal compression |
What does continuous flow (non-phasic with respiration) indicate? | Indicates more proximal obstruction and that the pressure in vein exceeds pressure changes within the abdomen during respiration |
What are 3 types of abnormal flow? | Non-spontaneous flow, pulsatile flow, and Alternating antegrade & retrograde flow |
If there is non-spontaneous flow where would the possible obstruction be? | Possible obstruction DISTAL to interrogation site |
What is associated with pulsatile flow? | Arteriovenous fistulae, Systemic venous HTN, Right heart failure (CHF), Pulmonary HTN (fluid overload) |
What is extrinsic pressure? | Pressure from surrounding structures can alter flow patterns. Ex- Pregnancy, or a tumor |
What is alternating antegrade and retrograde flow usually a result of? | Valve damage- it is abnormal |
What can retrograde flow occur with? | Can occur with normal respiration and/or upon provocative maneuvers (valsalva, augmentation) |
Increased reversal flow with proximal compression (valsalva) indicates what? | "Venous Reflux" |
What is May-Thurner Syndrome? | Left Common iliac Vein compression (& potentially thrombosis) by the Right Common iliac Artery. Right Common iliac Artery compresses Left Common iliac Vein |
What is Phlegmasia Alba Dolens? | Extensive iliofemoral DVT that causes marked swelling of lower extremity with pain, pitting edema and blanching |
What is Phlegmasia Alba Dolens also known as? | Milk leg or White leg |
What is Phlegmasis Cerulea Dolens? | An extension of Phlegmasia Alba Dolens, causes even more massive sweeling, more severe pain, and cyanosis of limb |
What happened to venous outlfow with Phlegmasia Cerulea Dolens? | Venous outflow is completely obstructed, May result in arterial insufficiency and venous gangrene |
What are some Non-vascular incidental findings? | Cysts & Hematomas, Edema, Abscesses, Enlarged lymph nodes, Tumors |
What are some Vascular incidental findings? | Aneurysms, Pseudo-aneurysms, Arteriovenous fistulas, and significant arterial disease |
Always confirm the presence of a thrombus with that? | Grey scale imaging |
Is it necessary to use angle correct in Venous Doppler? | NO |
What angle correction will increase sensitivity to flow? | 60-70 degress (must use on the JCC comp) |
Popliteal Cyst can mimic what? | Popliteal DVT, it will not be continous with the popliteal vein or lie along the popliteal atery course when turned to SAG. |
What does unilateral continuous flow indicate? | Proximal obstruction, or Extrinsic Compression from mass |
Bilateral continuous flow indicates what? | Shallow breathing, Supine PT, or IVC obstruction-usually bilateral swelling |
If Venous and Arterial studies are both ordered what do you do? | ALWAYS do Venous first |
What are the characteristics of Arterial symptoms? | Progressive symptoms, Intermittent pain, Foot/Limb Coolness, Rest pain in feet, and Very painful ulcers (gangrene, narcosis) |
What are the characteristics of Venous symptoms? | Acute onset, Persistent pain in calf/thigh, Redness of limb, Limb swelling/warmth, Local tenderness, "Homan's sign", Palpable Subcutaneous Card, Stasis Dermatitis, Shallow/irregular ulcers. SOB, CP |
What are 3 other imaging procedures? | Conventional Contrast Venography (uncommon), Computed Tomography Venography (used to define status of iliac veins) Magnetic Resonance Venography (used to detect DVT, Most useful when above the inguinal ligament) |
What is the primary treatment option for DVT? | Primary health treatment is Anticoagulation |
What are other treatment measures for DVT? | Gradient elastic stockings, and Thrombolytic agents and thrombectomies |