Home >> ALL ISSUES >> 2014 Issues >> How high-tech approach may reshape the autopsy

How high-tech approach may reshape the autopsy

image_pdfCreate PDF

Kevin B. O’Reilly

March 2014—Boosters of so-called virtual autopsy say it has the potential to revolutionize the practice of forensic pathology and could help increase the share of U.S. deaths subject to medical autopsy.

Dr. Thali

Dr. Thali

The technique involves the use of computed tomography, magnetic resonance imaging, and three-dimensional surface scanning technology to help resolve tricky forensic questions such as whether a woman was killed with a hammer or a bicycle wrench. The 3D scanning can help provide a “morphological footprint” to gauge against any kind of instrument that could have inflicted the damage, said Michael J. Thali, MD, chair of the Institute of Forensic Medicine at the University of Zurich in Switzerland. About 500 virtual autopsies have been conducted at the institute, Dr. Thali said in a June 8, 2013 lecture before the Royal Society of Medicine in London.

Postmortem imaging using CT and MRI—the former is better for evaluating skeletal injuries, while the latter excels with soft-tissue evaluation—can help give a 3D visualization of these blunt-force injuries, Dr. Thali said. He and his colleagues also have used the virtual autopsy approach in cases of strangulation, knife wounds, and more.

“These tools of imaging are opening a new world in forensics,” Dr. Thali added. Head-to-toe imaging is not the whole story, though. Dr. Thali’s team also has added postmortem angiography and biopsy to the mix. Inserting contrast media into the corpse, they can visualize the whole heart and lung system. One of the Swiss team’s innovations is the Virtobot, a robotic arm that can conduct a biopsy at the computer’s command. The team calls the virtual autopsy process “virtopsy.”

“Using techniques such as MRI and CT, and in addition biopsy and angiography, we can see 60 percent to 80 percent of the forensic causes of death,” Dr. Thali said. “In the future, that will change the world in forensics.”

In an interview with CAP TODAY, Dr. Thali adds that the virtual approach to autopsy can win more consents from next of kin. “Because virtopsy is nonbloody and nondestructive, relatives agree with this approach,” he says.

Postmortem imaging can help “add relevant findings to autopsy, plan the autopsy procedure, and is an excellent prescreening tool before the autopsy because you see what you have to expect,” Dr. Thali says. “Some of the forensic autopsy will be replaced by virtopsy, because you can answer the forensic autopsy questions based on virtopsy only.”

In addition to Switzerland, the virtual autopsy approach is being used in the United Kingdom, Japan, and Australia. Medical examiners from the Arab world also are showing interest, Dr. Thali says.

A recent study involving 120 adult deaths found that using a CT scan obviated the need for a traditional autopsy 38 percent of the time. Meanwhile, using CT and coronary angiography made invasive autopsy unnecessary in 70 percent of cases (Roberts IS, Traill ZC. Histopathology. 2014;64(2):211–217).

Some experts believe virtual autopsy could help overcome the short supply of forensic pathologists.

“There are very few practicing forensic pathologists and the workload is far in excess of what the current workforce can accomplish,” says Bruce Levy, MD, who practiced forensic pathology for two decades and is now associate professor of clinical pathology and director of informatics at the University of Illinois at Chicago. “So the ability to screen these bodies in advance using these noninvasive or minimally invasive techniques then frees the forensic pathologists to focus on those cases that really need the attention of a physician, and in a lot of ways helps us document injuries in ways we’ve never been able to do before.”

A handful of medical examiners in the U.S. have made use of CT scanners, most widely in Maryland and New Mexico. Since 2001, pathologists in the Armed Forces Medical Examiner System have done CT scans on every fallen service man and woman before conducting a traditional autopsy.

One hope is that the use of postmortem imaging could help increase the rate of medical autopsies in the U.S. By 2010, the rate had fallen from about half of in-hospital deaths in the mid-20th century to about 10 percent, Dr. Levy said during an October 2013 Web presentation sponsored by the Association for Pathology Informatics and Sunquest Information Systems.

Dr. Levy plans to pursue a pathology-radiology collaboration at UIC “to look at how useful this virtual autopsy would be in the medical setting.”

Dr. Stone

Dr. Stone

Some U.S. health care organizations are already implementing a form of virtual autopsy. About 230 corpses have been scanned prior to autopsy during the last three years as part of a Radiological Society of North America–funded research project at Massachusetts General Hospital. The imaging can help spot a pneumothorax that is difficult to detect during a traditional autopsy, says James R. Stone, MD, director of the hospital’s autopsy service. It has helped in other instances, too.

“We had a case where, for example, a nodule was recognized inside the arm—which we normally never would have even tried to find—that turned out to be a metastatic carcinoma that we wouldn’t have identified at all,” Dr. Stone says.

For now, the postmortem imaging at the hospital remains strictly a supplement to—and not a replacement for—traditional autopsy, Dr. Stone says.

“It’s less invasive, but there’s a trade-off,” he says. “Your sensitivity to making a diagnosis goes way down when you’re doing just virtual autopsy. . . . There are sophisticated questions we’re trying to answer in hospital-based, academic autopsies that go beyond what you can get with virtual autopsy. In the medical-examiner world, though, high-throughput virtual autopsy may have great value.”

CAP TODAY
X