What is the characteristic ultrasound finding in DVT?

The characteristic ultrasound finding in deep vein thrombosis (DVT) is absent venous flow. When using Doppler ultrasound to evaluate a suspected DVT, the absence of venous flow is a key indicator that a thrombus is present in the vein. Normally, veins should demonstrate a phasic flow in response to respiration and should compress easily under pressure.

In the case of DVT, the presence of a thrombus obstructs blood flow, leading to the absence of this normal venous flow pattern, which is a primary reason why Doppler ultrasound is favored for its ability to assess venous blood flow directly. This finding is critical in diagnosing DVT, as it confirms that a thrombus has formed and is affecting normal venous hemodynamics.

Other options such as thickened vein wall, increased venous diameter, and partial vein occlusion can be associated with DVT but are not definitive characteristics. Thickened vein walls can occur in other conditions, increased venous diameter can result from various factors including heart failure, and partial vein occlusion does not definitively confirm the presence of a thrombus like the absence of venous flow does. Thus, the absence of venous flow on Doppler ultrasound is the most indicative finding in