Which description best matches acute DVT findings on ultrasound?

• A. Acute DVT shows compressible veins with hyperechoic thrombus and abundant color
• B. Acute DVT shows incompressible veins, hypoechoic spongy thrombus within vein lumen, dilated vein, no collaterals, diminished or absence of color Doppler, continuous non-phasic spectral Doppler waveform even during augmentation/valsalva
• C. Acute DVT shows normal compressibility and no thrombus
• D. Acute DVT shows varicose veins only

Answer: (B)

Compression and Doppler findings are essential for identifying acute DVT on ultrasound. In acute cases, the vein becomes noncompressible because the fresh clot fills the lumen and adheres to the wall, making manual compression fail. The intraluminal clot is typically hypoechoic or spongy, contrasting with the surrounding blood-filled lumen. The vein is often enlarged proximal to the obstruction due to impaired flow. Color Doppler shows diminished or absent flow within the thrombosed segment, reflecting obstruction to blood entry. Spectral Doppler becomes nonphasic and shows little to no augmentation during maneuvers such as distal compression or Valsalva, indicating that normal bidirectional venous flow is disrupted. Over time, chronic DVT can become echogenic and develop collaterals, but acute DVT is classically described by incompressible, dilated veins with hypoechoic intraluminal thrombus, reduced or absent color flow, and a continuous nonphasic waveforms that do not augment.