The two best color doppler guys in the US are Dr Fred Lee in Rochester MI and Dr Duke Bahn in Ventura Ca. Reading a color doppler takes a lot of experience and skill and both of these doctors have done over 15,000 biopsies. It is well worth the travel to see either one of them.
The Datoli Clinic in Fla has a color doppler and Dr Bard in NY City also has one, but Lee and Bahn are by far the best.
As far as I am concerned the color doppler is the only way to go. I had 13 biopsies and an MRIS over 10 years that were all negative. The color doppler spotted a large tumor right away that everything else had missed.
JohnT