Is Computed Tomography Safe?

a nejm article in June 23, 2010 issue a article with the above title. it make a alert to me and many medical profesional. Are we doing good to pt or do more harm to patient by ordering CT scan.
According to this article, Radiation doses from CT scans are 100 to 500 times those from conventional radiography. Technical advances such as increased imaging speed have led to new CT scanning techniques that have also boosted doses. For example, the brain-perfusion scan uses sophisticated techniques for assessing regional blood flow and, even when done correctly, delivers a dose 10 times that of a routine brain CTTill now, it has not been shown directly that CT increases cancer risk, radiation is a known carcinogen, and extensive epidemiologic and biologic evidence links ionizing-radiation exposure with cancer. The National Research Council (NRC) has concluded that patients exposed to radiation in the range provided by a single CT scan have an increased cancer risk.
risk of single Ct is as high as 1/80.
Back to question, are we doing good by doing Ct scan. it depends but i totally disagree of detail CT scan or full body scan for check up if there is no symptom to suggest the source. Detail perfusion scan should be avoided unless indicated.