It used to be that the cause of death could only be determined by cutting a corpse open. But a new, virtual procedure developed by Swiss researchers is providing new insights into dead bodies. It could help identify previously undiscovered murders.
A couple is sitting at the breakfast table, when the wife suddenly complains about a severe headache. She jumps up, screams and collapses. But only when she stops breathing at around noon does her husband call an ambulance.
For the investigating criminologists, this case of unbelievable heartlessness raised one question above all: What could the man have done to his wife? Their surprising conclusion was that he did nothing, and that he was only guilty of a shocking lack of interest in his partner.
Forensic scientists with the Institute of Forensic Medicine at the University of Zurich in Switzerland diagnosed blood in the cerebrospinal fluid as well as a small aneurysm that had burst in the woman's head, which indicated that she had died of natural causes.
In another case, the Zurich police searched for the weapon with which a woman had been murdered. The forensic pathologists discovered tiny metal particles in the chin region. That find eventually led the police to the corpus delicti: a kitchen knife.
To solve both cases, it wasn't enough for the forensic scientists to simply cut open the sternum of the dead woman, in accordance with the standard procedure used when conducting a classic internal autopsy. To examine the circumstance of death, they didn't perform an autopsy on the body. Rather, they reviewed three-dimensional images of the dead women they had stored on their computer.
The method, in which forensic scientists combine images from powerful computed tomography (CT) and magnetic resonance imaging (MRI) together with surface scans of corpses is called "virtual autopsy."
More Efficient Autopsies
With the help of these combined imaging techniques, experts are now capable of gaining revealing and fascinating insights into the interiors of dead bodies. Most of all, they are finding fractures and hemorrhages that were not discovered during conventional autopsies.
Experts rave about the new method which is, at the very least, expected to complement classic autopsy. The idea is that after imaging a body, radiologists can draw abnormalities they encounter on the screen to the attention of forensic scientists.
"This enables forensic scientists to plan their autopsies much more efficiently," says Dominic Wichmann, a specialist in internal medicine at the University Hospital in Hamburg's Eppendorf district. In a study recently published in the journal Annals of Internal Medicine, Wichmann praises the benefits of virtual autopsies. Likewise, specialists with the United States Federal Bureau of Investigation (FBI) have been traveling to Switzerland lately to marvel at the computer-aided autopsies being performed at the University of Zurich.
Forensic scientist Michael Thali refers to the suite of devices he developed as "Virtobot." The idea for virtual autopsy began with the murder of a woman and the question of whether the killer had beaten her to death with a hammer or a bicycle wrench.
When he first tried to solve the mystery with the help of a computer, Thali and his staff were still housed in a cold barrack-like building on the campus of the University of Bern. "We were freezing in the winter, with only the computers putting off heat," says radiologist Steffen Ross, a member of the team for many years now.
It was only the move to the University of Zurich and a bequest from a wealthy ophthalmologist that led to the project's breakthrough. But it was poorly received in the professional world at first. "Initially we were decried as the enfant terrible of forensics," says Thali. Older champions of the autopsy room would often tersely refer to the idea of virtual autopsy as "crap," Thali recalls.
But a younger generation of forensic scientists, who have since taken over at most institutions, are much more open to the new technology. Michael Tsokos, the chief forensic scientist at Berlin's Charité Hospital, recently ordered a pared-down version of the Virtobot. "We use a version that a poor city-state like Berlin can afford," says Tsokos.
He characterizes the new possibilities of post mortem imaging a "revolution for forensic medicine," on a par with the discovery of the genetic fingerprint and hair analysis. "If (former German politician) Uwe Barschel or (singer) Kurt Cobain had been pushed into CT scan machines, their deaths wouldn't raise so many questions today," says Tsokos.
In addition to Charité, three out of a total of 35 forensic medicine institutes at German universities can now conduct virtual autopsies. But even in Berlin, scans are made of only a fraction of dead bodies due to a lack of technicians trained to use the equipment. Tsokos and his colleagues likewise felt clueless at first. The manufacturer hadn't provided anything resembling a manual on how to store, archive and interpret the data that had been obtained.
The complexity of the new procedure means that the once prominent role of the forensic scientist as the maestro of the autopsy table could fade. In Thali's laboratory in Zurich, he wouldn't even be able to operate his suite of machines without radiologists and engineers as equal partners at his side.
Dwindling Number of Autopsies
Furthermore, virtual autopsies could also lead to changes in ordinary autopsies. Nowadays most family doctors decide whether or not a person died of natural causes. But this practice has fallen into disrepute in Germany. Forensic scientist Tsokos suspects that about half of all homicides are currently being overlooked. He attributes this to doctors who simply have not mastered this part of their profession, or who do not treat it with sufficient seriousness.
Employees at the Institute of Forensic Medicine of the Hannover Medical School (MHH) in northern Germany agree with Tsokos's critical assessment. In an essay recently published in the German criminology journal Archiv für Kriminologie, the MHH experts write "that the post-mortem in more than 10 percent of cases is performed incompletely or not in accordance with legal requirements." They conclude: "The inspection of corpses currently does not satisfy the intended quality standards, especially not with regard to legal certainty."
In contrast to forensic medicine institutes, autopsies are hardly performed at all in hospitals anymore. Whereas a forensic autopsy is ordered by the public prosecutor's office in suspected murder cases, a pathologist can only perform a clinical autopsy with the permission of the family of the deceased.
There has been a drastic decline in this clinical form of autopsy in Germany in the last few decades. Only about 3 percent of all corpses of the recently deceased are opened up to inspect the internal organs. By comparison, 10 times as many cases end up in a pathology department in Austria.
The main reason is that relatives are often determined not to allow the body of their deceased family member be cut open, says specialist Wichmann of the Hamburg university hospital. The bereaved are far less queasy about virtual autopsy.
To their delight, the Swiss pioneers have also discovered that the new autopsy method makes it less likely that they will be confronted with excessively bloody experiences, such as in the case of a mountain climber who had fallen to his death in the Swiss Alps. The diagnosis reached by Thali's team included a shattered neurocranium, a fractured lumbar spine and a broken lower leg -- all done on a computer screen.
Other examinations, even those performed virtually, can still be messy. A dead body that remained undetected in an apartment for weeks and has begun to decompose still isn't easy to look at, even in the form of a 3-D image on a computer screen.
Translated from the German by Christopher Sultan
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