Physicians debate the value and risk of CT scans

The LA Times published an informative article discussing the proliferation and risk of CT scans.  It noted that since they were introduced in 1973, there are now 24,000 of the $1.2 million dollar machines installed in the United States, or 81 for every million persons.  In 2006, Medicare paid 2.17 billion dollars for CT scanning, double what it paid in 2000.  The medical basis for many of these tests, such as CT angiograms, is still characterized as "inconclusive".   Physicians ordered 68.7 million CT scans in 2007.  They administer a dose of radiation of 5 to 25 millisieverts, equivalent to more than a dozen standard x-rays, but they also can identify problems that no other medical test or device can diagnose.

Unfortunately, they also present a small risk of causing cancer, particularly in children.  Scientists believe that on occasion, the radiation separates an electron from an atom, creating an ion that damages a cell's DNA.  If that cell divides and multiplies, it has become a mutant cancer.  Doctors believe that an abdominal scan in a 5 year-old patient creates a 0.10% risk of triggering a fatal cancer: about 10 times the risk that the same test poses for a person over age 35.  Doctors predict that in future, the heavy use of CT scanning will add to each person's existing 42 percent risk of cancer, and may actually create two percent of all cancers treated in future.

While the MRI can be used for many CT functions and uses no radiation, it is not as sensitive as a CT scan and some patients cannot endure the time required inside the machine.  Still, as the number of machines proliferate, and as manufacturers sell them to physicians as a profit-source, questions arise about their over-use.  In a 2000 study by Highmark Blue Cross, thirty percent of 162,000 CT scans were deemed either unnecessary or not the best medical alternative.  In a 2003 survey of doctors and a recent report by the Government Accounting Office, regulators have documented significant over-use of scans for non-health related purposes (i.e., for convenience of patients, to eliminate potential liability, etc.) 

The government also confirmed that financial incentives play an enormous role:  doctors with their own equipment order two to seven times more tests than doctors who must send patients to another facility.  Some experts believe that as many as one-third of all scans should be replaced by an alternative form of testing, but when the machines are marketed to doctors, as in the Siemmons' sales brochure, as a profit-making venture capable of producing $400,000.00 per year in profit, we can expect that the percentage of machines outside hospitals to increase from the current 30 percent.