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Postmortem CT Scans Supplement and Replace Full Autopsies

As medical examiner and coroner offics nationwide face a severe shortage of forensic pathologists, New Mexico has pioneered the use of CT scans to reduce autopsy numbers and reduce costs.
Date Published
November 12, 2024

Bodies from across New Mexico come into the Office of the Medical Investigator (OMI) in Albuquerque daily. OMI pathologists examined about 4,500 bodies in 2022 and 4,500 the year before, which included those who were victims of homicide, died of a drug overdose, committed suicide, died of natural causes, and those who died in accidents. About half of the bodies receive full autopsies and the rest receive external examinations.

Those numbers would overwhelm many of the 2,000 medical examiner and coroner offices in the United States as they struggle with chronic funding issues, staff shortages, and outdated equipment. The acute national shortage of forensic pathologists who conduct autopsies and cause-of-death investigations makes the problem worse. The United States has only about 750 practicing forensic pathologists, according to the National Association of Medical Examiners.[1] In 2021, they were confronted with almost 21,000 homicides, nearly 100,000 drug-related deaths, and 225,000 people who died in traffic accidents, falls, unintentional poisonings, and other mishaps. Another 48,000 died from suicide.

The New Mexico OMI, with only seven forensic pathologists, is in one of the country’s most violent states;.[2] so how does the office address its high volume of work? OMI has developed an autopsy and postmortem examination system that is more in-depth, and yet more efficient, than most other medical examiner offices. Thanks to a past director, its unusual status as part of the University of New Mexico medical school, and generous funding from the state legislature, the New Mexico OMI has been using computed tomography (CT) scanning for the past decade on most of the bodies they examine, no matter the cause of death. 

Previously, OMI’s forensic pathologists performed full autopsies on 80% to 85% of the bodies that came into the office, said Natalie Adolphi, the director for OMI’s Center for Forensic Imaging and an associate professor in biochemistry and molecular biology at the University of New Mexico School of Medicine. “Now we have complete use of CT, and we scan everybody that comes in.” Because of that, she said, “the full autopsy rate is down to more like 50%, and maybe even lower.”

Obtaining the CT scanner and the specialized facility needed to house it, “was a combination of luck, the environment here, and individuals that have been committed to making it happen,” Adolphi said. Kurt Nolte, OMI’s former chief medical examiner, had the initial idea to augment autopsies with imaging. In 2010, “he was awarded the first big National Institute of Justice (NIJ) grant to fund forensic imaging research, and the imaging setup we have here now is largely his vision,” Adolphi said.

“Once we got going on his grant, we learned to scan a lot of bodies in a short period of time every morning,” Adolphi continued. “So, when the grant ended, we had the muscle memory to just keep doing it as part of our casework. And quickly it became clear that it really relieved the forensic pathologists of having to do a full autopsy on every case.”

Over the last decade, Adolphi and Heather J.H. Edgar, a forensic anthropologist and anthropology professor at the university’s health sciences center, have continued Nolte’s work through several NIJ grants, including projects to evaluate the way pathologists use CT scanning in routine casework, projects to compare MRI and CT scanning, and research to improve the identification of unknown decedents through imaging technology. Because New Mexico’s OMI is part of the university, it can receive federal research grants more easily than medical examiner/coroner offices not affiliated with major research institutions. Being part of the university also helped convince the state legislature to fund the CT facility when constructing a new OMI building in 2010. 

“I give credit to the New Mexico legislature who actually paid to build a building and construct a space for the CT scanner,” Edgar said. “Part of it is that we are centralized, the only office for the whole state, so they invested a lot upfront.” The CT scanner cost an additional million dollars, she said, “but they had the foresight of doing that, and it was impressive at the time.”

The timing was important, she added. If the OMI had not needed a new building, the scanner likely would not have happened. “If the timing is right for a given office and they happen to already be considering a new facility, and they are thinking about CT, then they can get a room designed for it and work it into the larger building budget,” Edgar said. “But to try to add CT into an older office, well, that is logistically hard.”

Dividends of Imaging 

The imaging program has paid significant dividends, the two scientists said. The annual, ongoing cost of the CT program is less than $400,000 per year, and the program saves approximately three full-time pathologist positions, which would cost OMI about a million dollars a year in salary and benefits.

Given the national shortage, Edgar said OMI could not hire three new pathologists, “even if we wanted to. It’s not just an issue of money. Where would we get three more pathologists?”

The volume of cases coming from across the state justifies the cost of the imaging program, Adolphi said. “If you don’t have a high enough case volume, you probably wouldn’t be able to realize the cost savings we do.”

Training is an additional issue. CT scans are typically interpreted by radiologists who are also in short supply nationally. Because “radiologists are way more expensive than forensic pathologists,” Adolphi said, her office has turned to training its pathologists to read the scans. 

“There is a learning curve for forensic pathologists to be able to interpret CT results,” she said. But because OMI is part of the university’s medical school it is possible to train the pathologists in radiological skills the CT requires.

The training is critical. Adolphi noted, “an office that doesn’t have a forensic pathologist who is comfortable with interpreting CTs, just imagining how they are going to get up to speed, who is going to train them, and how they’re going to learn to do this, is a barrier for many medical examiner offices.”

The use of CT scanners by medical examiners is limited to a handful of other locations in the United States, including the Armed Forces Medical Examiner System in Dover, Delaware. That office replaced its 15-year-old scanner with one designed specifically for forensic use in 2020. The new scanner is expected to save about $700,000 a year compared to the older machine.

Other medical examiner offices have part-time access to CT machines, Edgar said, but often don’t have the trained staff to take advantage of the machines. Adolphi noted that forensic CT scanners are more widely used in other countries and “are finding increasing application in the forensic death investigation setting, particularly in Japan and Australia, regions with many scanners but few forensic pathologists, and in Europe.” 

CT May Supplant a Full Autopsy 

The key value of a forensic CT scanner is that it can replace a full autopsy in some instances. CT scans can find injuries and other physical conditions that are sometimes missed in traditional autopsies and may determine if a full autopsy is needed. The scans can find injuries to the hands, feet, and face. Those areas are not routinely dissected in a traditional autopsy, but such injuries can indicate why a death occurred.

In some cases, an injury could be non-lethal, but when associated with a particular event is found to be a key contributor to a death. “Our chief had a case of a woman who was found 1.4 miles from the border wall with a broken foot (detected by a CT scan),” Edgar said. “Of course, she didn’t die of the broken foot; it was from exposure. But the broken foot was a key contributing cause, and that would not be detected in a normal autopsy.”

In one extreme case, human remains were encased in a large piece of concrete. “We broke it into chunks, and we were able to scan those,” Edgar said. Eventually, through scanning and rescanning, the investigators found images of metal pieces attached to bones. They concluded the person had likely been shot. “If we’d had to chisel that all out by hand to figure it out, well, I don’t think it would have happened,” Adolphi said.

Many of the bodies OMI examines are people who have died of drug overdoses. The CT can be valuable even in those cases. “We combine rapid toxicology with CT scanning to avoid doing autopsies in many drug cases,” Adolphi said. “The standard in an office that doesn’t have CT imaging is to autopsy drug overdoses. But the fentanyl problem has gotten so bad that some offices are trying to avoid autopsying all those cases. The way we do it is to combine a urine drug test with CT scanning to rule out other causes of death, along with other information such as medical history and evidence present at the scene. I think if there was federal funding for getting in-house toxicology that was sufficiently rapid and cheap, combined with CT scanning, that would really help with these cases. You’d need a standard protocol that everyone followed.”

Expanding Postmortem Scans 

Supported by an NIJ grant, Edgar has created the New Mexico Decedent Image Database (NMDID) as part of her work with the CT scanner. It includes more than 15,000 postmortem CT scans that “could be used for research in the fields of anatomy, pathology, growth and development, biomechanics, forensic anthropology and medicine, and public health,” she said, and at no cost to the scientific community.

More than 1,400 researchers from around the globe use the data. “There are people who have done safety research, biomechanics, and evolutionary research, and research on how to improve machine learning techniques for anatomy,” Edgar said. “There is research being done that would never have occurred to me.”

She noted research on identifying the differences between COVID-19 and other causes of pneumonia in lung scans as well as the impact of cancer treatments in the body. Scans from the database have been used to study the impact of safety harnesses and airbags on the body to improve auto safety. 

Saving images of scanned bodies could also help solve cold cases when the bodies have been buried or cremated, which is a particular problem if the victim is unidentified. “Once that happens, you can’t access those remains again for reanalysis,” Edgar said. “They may have DNA samples, but that’s it. But a CT scan would provide a virtual copy of those remains that could be reanalyzed. The CT scan could help with reinvestigating cases later.”

With online CT scans available, it might be possible to develop a system to help other medical examiner offices interpret their own scans. “If there were a centralized forensic tele-radiology system, radiologists could look at scans and assist pathologists with CT interpretation. That would help with offices trying to come up to speed and learn CT imaging,” Adolphi said. “It would also help with complex cases where you want a second opinion from an actual radiologist.”

In the future, artificial intelligence (AI) may provide pathologists with quick descriptions of a body’s health by analyzing the CT scan. A pathologist using CT and AI would have a good idea about a person’s overall health before they cut into the body. And an AI system could flag issues. “The idea of using AI to flag interesting findings that a human should then look at is a great way to use it,” Adolphi said. 

Date Published: November 12, 2024