Here's a recurring item in the news media, examples of costly, often unnecessary and even harmful procedures....

A University of Wisconsin-Madison team, led by Dr. Kristie Guite reviewed 978 abdominal and pelvic CT scans done on 500 patients. They used American College of Radiology guidelines to determine whether these studies were indicated or, in fact, appropriate.

52% of the patients "receiving abdominal CT scans, an advanced type of X-ray, got them for tests they did not need, exposing them to excess radiation that could raise the long-term risk of cancer"--i.e., the average excess radiation dose per patient was 11.3 millisieverts, about the equivalent of 113 chest X-rays.

At the dose seen in the study, one in 1,000 patients could get a radiation-induced cancer," Guite said adding that "This could lead to up to 23,000 radiation-induced cancers per year"  Also, "Many of the scans they looked at involved the use of a contrast agent," implying that some "many institutions may be doing the extra studies for good measure, or because their machines are automatically set to do them..... But .... it was possible some centers were doing the extra scans because they may get paid more for them."

Steenhuysen J.  "Abdominal CT Scans Overused - U.S. Study" Reuters Nov 30, 2009 6:28pm EST

See also the following discussions of elevated cancer risk after CT scans:

Berrington de González A, Mahesh M, Kim K-P, Bhargavan M, Lewis R, Mettler F, Land C. "Projected Cancer Risks From Computed Tomographic Scans Performed in the United States in 2007." Arch Intern Med. 2009;169(22):2071-2077.  [Results:  They estimated that approximately 29,000 excess cancers (95% UL, 15,000-45,000) could result from CT scans performed in the US in 2007.]

Redberg RF. "Cancer Risks and Radiation Exposure From Computed Tomographic Scans: How Can We Be Sure That the Benefits Outweigh the Risks?" [Editorial] Arch Intern Med 2009;169 2049-2050. [Subscription required].  In brief, it says there is far more radiation from medical CT scans that had been recognized.

In forty-year-old women undergoing a CT coronary angiogram, 1 in 270  will get cancer from the procedure.  In general, 15 000 persons may die as a direct result of CT scans physicians done in 2007.  In addition, as the sensitivity of these tests increases "incidental findings lead to additional testing (and often more radiation), biopsies and anxiety....the explosion of CT scans in the past decade has outpaced evidence of their benefit. ...To avoid unnecessarily increasing cancer incidence in future years, every clinician must carefully assess the expected benefits of each CT scan and fully inform his or her patients of the known risks of radiation."