Growing use of medical imaging may be increasing cancer risk

Growing use of medical imaging may be increasing cancer risk 
http://www.cbc.ca/health/story/2009/08/27/radiation-ct.html
Some question necessity of high-radiation CT, heart scans 

"As many as two-thirds of adults underwent a medical test in the last few years that exposed them to radiation and, in some cases, a potentially higher risk of cancer, a study in five areas of the U.S. suggests."