My ds had an echogenic bowel at his 20w scan, again the radiologist didn't know what it meant so she refered me to a specialist unit for a more detailed scan.
As I learnt at the special scan, and as others on this thread have said, echogenic spots can be soft markers for many conditions. I also had a set of blood tests to see whether I might have had any illnesses during the pregnancy that might have caused the spot (rubella and toxoplasmosis are the only ones that I recall), which all came back clear - they just confirmed that I was immune to most of the potentially dangerous illnesses!
The specialist scan was amazing - even more so than the 'ordinary' scans had been. We saw so many amazing and wonderful things - except the sex of my baby, as they had asked whether I wanted to know and I had said 'No'. The consultant decided that, as there were no other soft markers, no problems highlighted by my blood-tests, and a very good statistical result from my 16w blood test (Triple?), that the echogenicity was probably caused by the foetus swallowing blood in the amniotic fluid, that had come from a small bleed in the placenta. I had never been aware of anything happening, but something must have done becuase the scan showed some scarring on the placenta. He decided that I should have scans every 3-4wks, and by about 35wks the echogenicity had faded completely and everything was normal.
Ds was born at term, healthy and with no problems. I hope this reassures you. I too was told that the technology was getting so advanced that in a sense there was now too much information, and people couldn't yet analyse it all, so were extra-cautious. My MIL had a friend whose dd went through exactly the same as I did, with the same results.
Good luck!