Tuesday, November 27, 2007
Investigators Explore Applications of Image-Assisted Autopsy in Cases of Traumatic Death and Possible Elderly Abuse
Researchers from the University of Maryland School of Medicine and the Office of the Chief Medical Examiner, State of Maryland, say that "virtual autopsy" using a CT scanner may offer a reliable alternative to conventional autopsy in certain cases and serve as a tool for gathering forensic evidence. The researchers are presenting findings from their preliminary study at the Radiological Society of North America meeting, November 27, 2007, in Chicago.
"CT is a sensitive imaging tool for detecting injuries and cause of death in victims of blunt trauma," explains Barry Daly, M.D., professor of radiology at the University of Maryland School of Medicine. "Our study shows that when there are major injuries, such as those resulting from a motor vehicle accident, CT may provide enough information so that a conventional autopsy would not be needed."
"If we can show that image-assisted autopsy is as reliable as physical autopsy, it has the potential for a significant savings in time, effort and expenditure. It may also offer a possible compassionate alternative for those families whose religious and personal beliefs preclude a full autopsy," says David R. Fowler, M.D., chief medical examiner for the state of Maryland.
In the study, investigators used a whole-body, multi-detector CT to evaluate the cause of death and forensic evidence in 20 cases: 14 were victims of blunt trauma and six were victims of a penetrating wound made by either a knife or gun. Two radiologists reviewed the scans to determine a cause of death and compared their conclusion with the results of a conventional autopsy performed by state forensic medical examiners.
The CT evaluation matched the medical examiner’s cause of death in all 14 blunt trauma cases and in five of the six penetrating wound cases. In terms of evidence gathering, the radiologists and forensic medical examiners concluded that the CT findings were comparable to conventional autopsy in 13 of the 14 blunt trauma cases. In five of the six penetrating wound cases, they found that CT provided additional information to help with the investigation, including locating all 26 major ballistic fragments recovered from the victims in the conventional autopsies.
"Autopsy is mandatory in deaths involving gunshot wounds, so CT may serve as a powerful complement to the conventional exam," says Dr. Daly, who is also a radiologist at the University of Maryland Medical Center. "Performing CT imaging first may speed up a conventional autopsy, especially when it comes to locating ballistic fragments, which are important in criminal investigations."
Most states require an autopsy in cases of sudden or unexplained death, which resulted in approximately 4,000 full autopsies last year in Maryland. While a forensic medical examiner requires several hours to conduct a full autopsy, a multi-detector CT scan along with the interpretation of the images, can be performed in about 30 minutes. Also, the CT is non-invasive, so it does not damage or destroy key forensic evidence.
"CT has been used in autopsies of American soldiers and in a few countries around the world. While the preliminary results are promising, more research is needed to show that CT could be widely used within the U.S. medical examiners’ system," says Dr. Daly.
The researchers have also received a $292,000 grant from the National Institute of Justice, part of the U.S. Department of Justice, to look at the use of CT autopsy to investigate deaths related to possible elder abuse. The two-year project will evaluate 80 cases referred to the Office of the Medical Examiner because of suspected abuse.
"The use of image-assisted autopsy to detect possible abuse of the elderly offers great potential," says Dr. Fowler. "Our office and those of medical examiners nationwide are seeing increasing numbers of suspected elder abuse cases. With some state governments considering mandatory autopsies for all deaths in residential care and assisted-living facilities, we have been challenged to find new ways to accurately and rapidly assess the causes of these deaths."
Investigators will use a full-body CT scan that generates up to 3,000 detailed, high-resolution images. Radiologists will then use special computer software to reconstruct the separate images into three dimensional views, tailored to the specific needs of each case. The imaging evaluation will be compared with results of the medical examiner’s visual assessment and full autopsy.