Virtual Autopsies Help Shed Light on Possible Child Abuse

Radiology techniques are being increasingly used to conduct post-mortem investigations that are less slice-and-dice, more scan-and-shoot.

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Jan 16 2017, 3:00pm

Image: congerdesign/Pixabay

On TV, autopsies can be gory affairs, but in real life, radiology techniques are being increasingly used to conduct post-mortem investigations that are less slice-and-dice, more scan-and-shoot.

These less invasive procedures can be especially useful in sensitive situations. And few situations are more sensitive than those where child abuse is suspected. Inaccurate autopsy results can ruin lives: of grieving parents or of discredited medical professionals. So it's crucial to tread very carefully when interpreting these results. Forensic information should be examined hand-in-hand with medical, social work, psychological, and other histories.

Globally, traditional autopsies are becoming less frequent, both for adults and for children. In the US, for instance, half the people who died in hospitals 50 years ago would have been autopsied. The rate is around 5 percent now.

One reason is that imaging tools like computed tomography (CT) and magnetic resonance imaging (MRI) scanners are being used for diagnosis while patients are alive. So there's more confidence about causes of death, even though in adults, these assumptions are wrong about 1/3 of the time. And when it comes to children's deaths, autopsies provide new information almost half of the time (according to a 2010 paper).

These same imaging technologies are being increasingly used in autopsies, too. These range from simple X-rays to PET (positron emission tomography) scans.

When it comes to children, this isn't a matter of just scaling down the post-mortem procedures applied to adults. Causes of death are very different for kids (and for kids of different ages), and of course their anatomy is distinct from adults'. Knowing how tissues of different sizes and bones at different stages of development show signs of trauma requires experts in pediatric post-mortem imaging—and there are very few of these at the moment.

There are some critical differences between imaging of live children and adults with suspicious injuries. An obvious one, explained by Sabah Servaes, a pediatric radiologist at the Children's Hospital of Philadelphia, and the chair of the Society for Pediatric Radiology's Child Abuse Imaging Committee, is that "children often can't tell you what happened to them." This can be especially true if a trusted authority figure has been responsible for violence.

Fractures of a child's left femur and right ribs. Servaes calls the latter "very unusual in a child without history of significant trauma, and thus very suspicious for child abuse". Image credit: Sabah Servaes.

In addition, adults are more likely than children to have fractures at different stages of healing, which isn't often seen in toddlers or babies. Owen Arthurs, a pediatric radiologist who leads two recently formed task forces dedicated to pediatric imaging, says of infants, "Accidental trauma doesn't really happen in children who can't get around or don't walk." Thus, in the UK, "Every baby under 1 year of age who is deceased currently gets a whole-body skeletal survey using X-rays."

When it comes to deceased children, those who may have been harmed deliberately—which Arthurs stresses would be a minority, perhaps only 5 percent—"would often not have outward signs of abuse." Advanced imaging could help uncover signs that wouldn't otherwise be obvious, like blood in the head, lacerations in the liver, or fractures in areas that are common in abused children.

Specialists have already started to report cases where digital techniques have uncovered things that weren't revealed in traditional autopsies. A tragic example is gas in the central thoracic cavity of a 3-year-old girl, which showed that she was alive at the time of her hanging.

One advantage of these techniques is that images, unlike bodies, don't decompose. Another is that CT, for example, can be used without removing a body from a coffin or body bag—making the experience slightly less harrowing.

It's hard to combat child abuse if we can't even identify it.

To further advance the field, Arthurs said, "We need to improve the imaging techniques to make them post-mortem-specific." One such technique is diffusion-weighted MRI, which only recently has started to be applied to the dead. Diffusion-weighted MRI measures water levels in tissue, which change after death and thus may help radiologists to identify the timing of death.

The Post Mortem Imaging Task Force of the European Society of Paediatric Radiology published a consensus statement last summer. And the Paediatric Imaging Committee of the International Society of Forensic Radiology and Imaging is working on a guideline statement, to be published in 2017, on post-mortem CT when it comes to possible child abuse. The aim is to standardize procedures across different hospitals, so that professionals can share experiences. Ultimately this could also give the general public and legal systems a better understanding of the applications of the technology.

Servaes, who volunteers with the Pennsylvania Attorney General's Medical/Legal Advisory Board on Child Abuse to provide expert advice on possible child abuse, says that while "no test is 100 percent perfect…there are some things that the vast majority of people would look at and reach certain conclusions." Having standardized protocols for post-mortem imaging could further help to reduce the gray area in cases involving tragedy—ones where you really don't want to get anything wrong.

Standardization may be tough to achieve when countries have such different funding mechanisms for post-mortem investigations. The UK is a leader when it comes to post-mortem digital imaging of children. One reason is the public funding structure, where for example "the centrally agreed fee for perinatal autopsy can include any form of imaging," as Arthurs says.

In the US, there's no centralized funding for autopsies. Neither Medicare nor private health insurers directly pay for these. "The decision to obtain post-mortem imaging and how it is obtained and paid for are determined by local medical examiner/coroner jurisdiction," Vincent Palusci of the American Academy of Pediatrics told Motherboard. "Many have agreements with hospitals, but this is not universal."

1–2 percent of American kids are abused each year—and those are just the confirmed cases. According to a 2016 article Servaes co-authored, "In young children, 20 percent of fractures caused by abuse may be incorrectly attributed to other causes." And shockingly, physical abuse is most common among children younger than 2.

It's hard to combat child abuse if we can't even identify it. Using the full arsenal of tools available— legal, social, psychological, and (in the case of the advancing field of post-mortem imaging)technological—could build a more accurate picture of just how common abuse is.