Laura S. Marshall, firstname.lastname@example.org
CT scanning a dead body isn’t really all that different from scanning a living person, but there’s one very noticeable difference: The radiologist doesn’t have to worry about the patient moving around inside the scanner.
“There’s no moving or breathing to deal with,” said Dr. Barry D. Daly, professor of radiology, chief of abdominal imaging and vice chairman of research for the department of diagnostic radiology at the University of Maryland Medical Center in Baltimore. There is also no concern about radiation dosage, he said. “But there’s no benefit of IV contrast or oral contrast,” he added – after all, without flowing blood or working digestive organs, contrast substances can’t travel throughout the body.
Daly is at the forefront of the American CT autopsy movement. Also known as “virtual autopsy,” it allows a medical examiner to investigate cause of death using a computed tomography scanner instead of a scalpel.
A CT image from a virtual autopsy shows multiple skull and facial bone fractures resulting from fatal blunt trauma to the head of a pedestrian struck by a car. Courtesy of the Radiological Society of North America.
A team headed by Dr. Michael J. Thali, managing director of the Institute of Forensic Medicine at the University of Bern in Switzerland, has pioneered “virtopsy,” a technique that Daly said is similar to his own.
“We’re the first civilian group in the US to do it to any degree,” he noted. “Most of the work done in this country has been done on casualties of the wars in Iraq and Afghanistan.” That work has been done at Dover Air Force Base in Delaware.
“We do head-to-toe imaging,” Daly said. “We scan in very thin sections of 1-mm-slice thickness so we can have high-quality reconstruction. We reconstruct most body parts in at least two or three planes.”
Information from the referring medical examiner’s office as to the suspected cause of death – for example, a shooting or a motor vehicle accident – gives Daly and his team an idea of what they’re looking for, although he said some injuries show up better than others.
“For the brain, it’s pretty good,” Daly said. “For spinal bone injury, it’s excellent. For organs in the abdomen – we can see them, but it’s a little limited.” He noted that the team is generally looking for “major findings such as a severely traumatized brain or a large intracranial hemorrhage or major abdominal bleed, things like that.
A CT image from a virtual autopsy depicts internal damage to the brain with diffuse cerebral injury. Blood is present in the right sylvian fissure. Air has entered the skull because of the skull fractures. Courtesy of the Radiological Society of North America.
“The average victim of a major motor vehicle accident has up to eight major injuries, usually quite a lot of findings that are pretty obvious on CT.”
When virtual autopsy eventually is adopted as a standard practice, the impact on forensics will be great. “Medical examiners are really very enthusiastic,” Daly said. “In time, it will not be necessary for them to do all the autopsies that they do now.” In times of budget and staff shortages in all kinds of fields, it must sound promising indeed to replace a procedure that takes hours with one that takes, according to the Radiological Society of North America, 30 minutes from scan to results.
The idea is not to get rid of traditional autopsies altogether, he stressed, but to use the CT method as a triage tool. “The logic would be to – in certain settings, like major trauma – do a scan first, then determine whether it’s truly necessary to proceed [with a traditional autopsy],” Daly said. He and his team estimate that 30 percent of the autopsies currently performed could be eliminated under such a program.
“The public isn’t terribly enthusiastic about autopsies anyway,” he added. Some religions don’t like the idea of the body being cut open, he said, and distraught family members often are resistant to a traditional autopsy, even when their religious beliefs permit it. “And medical examiners don’t like doing an autopsy when there’s tremendous resistance. They’re aware it’s a really emotional time for the family.”