The natural dynamic behaviour of the prostate gland phantom when punctured by the needle.
Needle Reverberation (echo) occurs when the beam of sound waves is directed along the long axis of a hollow needle. Reverberation occurs within the core of the needle, resulting in the appearance of ' several needles' in the ultrasound image.
The true needle is the one closest to the ultrasound probe ( the lowermost one).
Needle Tracks in a Phantom
In the prostate gland image above, it is easy to distinguish between the penetrating needle and the old needle tracks:
