Doppler vein signal

Fig. 12.4a,b. Rupture of the deep dorsal vein curved arrows) following vigorous intercourse, a The torn vessel presents with posttraumatic thrombosis identified by presence of echogenic material within the lumen, b Color Doppler interrogation shows absence of color signal within the obliterated vessel... 

In patients with thrombophlebitis of the dorsal vein (Fig. 17.4), grey-scale and colour Doppler ultrasonography show thickened vessel wall and complete or segmental thrombosis (Dicuio et al. 2005 Abaci et al. 2006 Shamloul and Kamel 2006), t diich can be occasionally associated with thrombosis of the circumflex veins. In complete thrombosis, no Doppler signal is recorded. 

In colour Doppler, similar processing is applied across the image. The colour Doppler signals are shown as an overlay conventionally coded in shades of red for flow towards, and blue for flow away from the transducer (Fig. 1.3). Another way to display flow information depicts only the Doppler signal intensity as a power Doppler scan. It has higher sensitivity than frequency-based colour Doppler but lacks directional information and so is more useful for the small vessels, for example, in tumours, than for the portal vein where flow direction is important. 

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