1. Follicle aspiration with interactive three-dimensional digital imaging (Voluson): a step toward real-time puncturing under three-dimensional ultrasound control∗ 
Wilfried Feichtinger, M.D. 
Fertility and Sterility 
Volume 70, Issue 2, Pages (August 1998)
DOI: /S (98)

2. FIGURE 1
Three-dimensional US display. Within the scanned volume, three matched and dynamically linked orthogonal sector planes are generated within 2 seconds and displayed simultaneously. The tip of the needle is checked for its correct position (arrowheads). Meanwhile, interactive rendering is computed automatically and appears on the screen (bottom right), providing additional spatially animated information about the exact position of the needle tip.
Fertility and Sterility  , DOI: ( /S (98) )

3. FIGURE 2
The “power Doppler” trick. Twisting and slightly pushing the needle back and forth creates a simulation of flow, which is recognized by the machine’s color-coding software. The entire needle is clearly visible in bright red color. (Seeing a real flow inside steel is technically impossible!) In the yellow area (arrowhead), the needle tip surrounded by flowing follicular fluid (red area) at the onset of aspiration.
Fertility and Sterility  , DOI: ( /S (98) )