From the Scientific American
December 03, 2003
Television shows like CSI and Law & Order have brought forensic science into the living room, but actual autopsies are not for the faint of heart. A new technique may change that, however. Today at the annual meeting of the Radiological Society of North America in Chicago researchers described Virtopsy, a virtual autopsy procedure that requires neither scalpels nor a strong stomach.
So far, 100 virtual autopsies have been performed in Switzerland as part of the research program, and the results have started to appear in courtrooms. "The virtual autopsy does not destroy key forensic evidence, which may be damaged during a classic autopsy," notes speaker Michael Thali of the University of Bern's Institute of Forensic Medicine. "It can also be used in cultures and situations where autopsy is not tolerated by religion, such as in the traditional Jewish faith, or is rejected by family members. Some people do not like the idea of autopsy."
The procedure utilizes two types of imaging--computed tomography (CT) and magnetic resonance (MR)--to generate a 3-D computer model of the body. If a victim was murdered using a weapon, a surface-scanning program can document the wound and garner information. Time of death is established by measuring the changing brain metabolites given off as the body decomposes. "It's then possible to merge all of this information from the body's inside and outside into one data set on the computer," Thali explains. "We now have 3-D, nonsubjective information that can easily be presented in court--without showing graphic, horrible images that may shock people." The process does have its limitations, however. For one, it is expensive compared with the old-fashioned exam. In addition, it cannot be used for post-mortem angiography--a procedure that can provide important information about a person's cardiovascular health at the time of death. Still, Thali predicts the technique's benefits will make it an acceptable alternative to current practice within 10 to 15 years.
A second virtual procedure described at the meeting on Monday holds promise for living patients. Perry J. Pickhardt of the University of Wisconsin Medical School in Madison presented results of a study investigating the effectiveness of virtual colonoscopy for colorectal cancer screening. The team performed both conventional and virtual exams on 1,233 patients, most of whom had an average risk of developing polyps, or benign growths that could later develop into colon cancer. The virtual approach detected slightly more polyps (92.6 percent of growths larger than eight millimeters) than conventional testing did (89.5 percent). Colon cancer is the second leading cause of cancer death and is highly preventable, notes study co-author J. Richard Choi of the Walter Reed Army Medical Center. "The goal of screening with virtual colonoscopy," he says, "is to increase the number of patients that would participate."