From New Scientist, 12 June 1999
by Rob Edwards
ULTRASOUND SCANS can stop cells from dividing and make them commit suicide.
A research team in Ireland say this is the first evidence that routine scans, which have let doctors peek at fetuses and internal organs for the past 40 years, affect the normal cell cycle.
A team led by Patrick Brennan of University College Dublin gave 12 mice an 8-megahertz scan lasting for 15 minutes. Hospital scans, which reflect inaudible sound waves off soft tissue to produce images on a monitor, use frequencies of between 3 and 10 megahertz and can last for up to an hour
The researchers detected two significant changes in the cells of the small intestine in scanned mice compared to the mice that hadn't been scanned. Four and a half hours after exposure, there was a 22 per cent reduction in the rate of cell division, while the rate of programmed cell death or "apoptosis" had approximately doubled.