Once a common medical procedure, the standard autopsy is passing out of use. In the 1970s bodies underwent postmortem examination in nearly 20 percent of deaths in the U.S. By 2007 the rate had fallen to 8.5 percent of all deaths and to only 4.3 percent of deaths caused by disease.
The reasons for the decline are well documented. Autopsies reveal medical mistakes, making doctors and hospitals uncomfortable. Medicare and private insurance do not reimburse providers for the procedures, so families must pay in full. And in the increasingly diverse U.S., members of some religions, such as Orthodox Judaism or Islam, object to dissecting a body after death.
Yet autopsy is a time-honored and reliable tool for confirming, or questioning, the actions of both medicine and law enforcement, so pathologists have looked for a viable alternative. Inspired by rapid technological improvements, researchers in several countries have been exploring the possibility that medical imaging—in particular, MRI and CT scans—might substitute a “virtual autopsy” for the more traditional variety.
“The findings so far are mixed,” says Elizabeth Burton, a visiting associate professor of pathology at Johns Hopkins University. Virtual autopsy, she says, “is better for examining trauma, for wartime injuries, for structural defects. But when you start getting into tumors, infections and chronic conditions, it's not as good, and I doubt it will ever be better.”
After about a decade of research, proponents concede that various difficulties—including high cost, competition for access to imaging machines and some inherent limitations of the technology—will likely prevent virtual autopsies from fully replacing the hands-on version. Nevertheless, the new techniques are answering cause-of-death questions that have frustrated traditional autopsies and are sidestepping religious objections. By enhancing medical education and suggesting improvements in emergency care, virtual postmortem examination is helping the living, too.
Postmortem imaging began as a laboratory technique in legal investigations. Dissection usually destroys tissues, but a research group in Bern, Switzerland, recognized that advances in imaging technology would let them look deep into tissues while preserving evidence. In the early 2000s they combined MRI and CT scanning with computer-aided 3-D reconstruction to prove causes of death for difficult cases, which included drownings, flaming car crashes, and severe injuries to the skull and face.
Their process, which they dubbed “virtopsy,” ignited interest in applying postmortem imaging to other forms of traumatic injury. Since 2004 the U.S. military has performed x-rays and CT scans on the bodies of every service member killed where the armed forces have exclusive jurisdiction—that is, not just on battlefields abroad but on U.S. bases as well. Imaging “is an adjunct to the traditional external and internal postmortem exam,” says Edward Mazuchowski, chief deputy medical examiner in the Armed Forces Medical Examiner System. “It allows us to identify any foreign bodies present, such as projectiles. X-rays give you the edge detail of radio-opaque or metallic objects, so you can sort out what the object might be, and CT, because it is three-dimensional, shows you where the object is in the body.”
Along with analyzing causes of death, the virtual exams help to assess the accuracy of medical care in the field. Through imaging, examiners can detect whether medical devices, such as breathing tubes and long needles that can decompress a collapsed lung, performed as expected or fell short. Those analyses spur improvements such as lengthening needles to make sure they penetrate soldiers' sturdy musculature, as well as redesigning body armor to protect against the shrapnel scattered in unpredictable patterns by improvised explosive devices.