An Interesting Case
By Beth W. Orenstein
Radiology Today
Vol. 25 No. 4 P. 10

The use of forensic radiology is gaining traction in the United States.

Thanks to rising caseloads across every state, the United States needs at least double—if not more—of the 750 fulltime, board-certified forensic pathologists it has now, according to the National Association of Medical Examiners (NAME). As a result of the shortage, some autopsies are taking longer than 60 to 90 days, NAME says. Could forensic radiology be an answer? Absolutely, says Robin Hines, MD, MS, FASER, a recently retired emergency radiologist in Spokane, Washington, who has an interest and experience in forensic radiology.

“It’s absolutely clear to me that medical examiners in this country don’t have the bandwidth to be able to do the number of labor-intensive conventional autopsies needed in a timely manner,” she says. Put a deceased individual in a CT scanner, and within minutes, “you have most of the information you need. To me this is a brilliant idea.” It is true that forensic radiology is not a 100% replacement for an autopsy, Hines says. “There are some things you cannot identify by CT (or other imaging techniques) but it’s a very useful adjunct, and, in cases where you can’t do an autopsy, it can provide answers.”

Forensic radiology is not a new specialty, says Summer J. Decker, PhD, the director of the Center for Advanced Visualization Technologies in Medicine and a professor of radiology and pathology at the Keck School of Medicine at the University of Southern California (USC). “It dates back to nearly the original use of the X-ray,” Decker says. X-rays were discovered in 1895 by the German physicist Wilhelm Conrad Roentgen. “The first use of forensic X-ray in Europe was in 1896. In the United States, it was just a few years later, in 1898,” Decker says. However, it wasn’t until 1977 that researchers in Germany first reported using forensic CT. The researchers used forensic CT to assess acute injuries to the brain from gunshot wounds. In the 1990s, a team from University of Bern in Switzerland, now in Zurich, established a protocol for virtual autopsies or “Virtopsy.” The concept has since taken off in Europe, the United Kingdom, Asia, and Australia. Decker says the rise in “virtual autopsies” or image-guided autopsies coincided with improvements in CT, MRI, and 3D technologies as scanners became better and faster. Today, Decker says, postmortem imaging is standard practice in many European countries including the United Kingdom, Australia, and Asia. “In some countries, they supersede doing a full autopsy on the body and a traditional autopsy is only done if needed,” Decker says.

In experienced hands, forensic imaging can provide as much information, if not more, as a conventional autopsy in a fraction of the time, Hines says. “When I started practicing 34 years ago,” Hines says, “and we wanted to know if someone injured their aorta in a high-speed collision, we would inject dye into their arteries and do a conventional angiogram. It was a time-consuming and labor-intensive procedure,” she says. “With the availability of high-resolution CT scanning we began to examine these patients by CT and, for some time, we did both a conventional angiogram and CT scan to be sure that CT was not missing injuries.” Eventually, the examiners were able to rely mostly on CT because of its high degree of accuracy “and save a tremendous amount of time, increasing patient throughput,” Hines says.

Overseas forensic CT and postmortem angiography have increased in use, Decker says. “That’s true, too, of US sites that already utilize this technology,” she adds.

Expanding Use
Forensic imaging isn’t used as widely in the United States as it is in other countries, says Thomas Ptak, MD, PhD, MPH, a professor of radiology at the University of Maryland School of Medicine. One of the reasons, Ptak says, is that few forensic pathologists have access to CT scanners at their medical examiners’ offices. Not only do the medical examiner offices have to buy the scanners, but they also need assistance running them as well as the training and skills to read the images, Ptak says. Some jurisdictions are willing to make the substantial investment, and some are not. “Forensic this country,” Ptak says, but it’s not there yet, and some of the big reasons are financial and lack of support from the states or counties that run the medical examiner offices. Also, while the number of programs that train forensic radiologists is growing, it’s still small. Several new programs are starting up, including at the University of Maryland in Baltimore, where Ptak works. Decker says she recently moved to USC Keck School of Medicine because it wants to establish a forensic radiology training program.

Organizers of radiology conferences have seen a growing interest in the topic and held sessions on it. RSNA has had panels on forensic radiology for decades, including at the most recent meeting in November. “But there is a growing interest in the topic now,” Decker confirms.

Marc Camacho, MD, an emergency radiologist at the Mayo Clinic in Phoenix, and an associate professor of radiology at the Mayo Clinic College of Medicine & Science, first suggested a session on forensic imaging as a part of the 2020 annual meeting of the American Society of Emergency Radiology (ASER), which, thanks to COVID, had to be held virtually. The reception was far greater and more enthusiastic than Camacho or anyone else anticipated. “Because of the response, it was renewed for the following annual meeting in 2021, a hybrid meeting, where it was highlighted as a Self-Assessment Module session, boosting its visibility in the program. “[It] too was extremely well received,” Camacho says. It also led to doing a similar session at RSNA in November 2021. Camacho is working on organizing a session at ASER again this year, which runs from September 11-14, 2024, in Washington, D.C.

Camacho believes the interest in forensic radiology among ASER members is due to the crossover with trauma imaging. “Obviously, that’s what we do in emergency radiology so forensic imaging is a natural extension” for emergency radiologists, he says. Speakers have addressed the use of forensic radiology in identifying victims of mass casualty events, such as shootings and plane crashes, as well as in living victims of abuse. Speakers also have addressed how forensic radiology can be useful in criminal cases. “There are just so many different applications,” Camacho says. “It’s really more of a mindset of trying to put together a piece of the puzzle of what happened to the patient through the imaging findings and so for radiologists that is what they do anyway, only on live bodies. It’s not terribly off the beaten path for those of us who work in trauma and the ED.” Emergency radiologists can assist in reading postmortem imaging, but reading postmortem imaging takes further training, Decker notes.

Very few are employed full time as forensic radiologists in the United States. “It’s more something you would do in addition to a typical radiology position,” Camacho says. “You might be called for a consultation on a particular forensic case—especially if you’re recognized as an expert in the field of imaging that would be most helpful. Forensic imaging requires a slightly different skill set “as there is a directed purpose beyond providing a radiology report for clinical care, such as providing evidence for a criminal prosecution, many times utilizing postmortem imaging,” Camacho says.

Hines adds that live tissue looks different from dead tissue. “It’s much like the difference between being a surgeon in the OR and a pathologist in the autopsy suite,” she says.

Decker says that, because the heart is not pumping and blood is not circulating, the deceased do not respond the same to imaging techniques such as MRI pulses and contrast, which are sometimes used with CT. “Because the images do look different in the dead, you have to train to interpret those images,” she notes. “You also have to learn how to provide the necessary information that the medical examiners need for their case reports and courts.”

Piquing Interest
In 2011, the International Society of Forensic Radiology and Imaging (ISFRI) was established in Switzerland in a worldwide effort to educate practitioners and promote and develop the field of forensic imaging. The members have established worldwide standardized methods that have even been adopted by world law enforcement agencies, such as INTERPOL. Since the founding of the society, ISFRI has been publishing the only peer-reviewed journal dedicated to the field of forensic radiology, Forensic Imaging (previously Journal of Forensic Radiology and Imaging), covering various noninvasive and minimally invasive examination methods in a forensic context using postmortem imaging and visualization technologies.

For more than 15 years, the University of Zurich’s Institute of Forensic Medicine has presented a “Virtopsy”—a minimally invasive imaging autopsy—training course each year in Switzerland. Pathologists and radiologists are in the same room during instruction. “They train side-by-side,” says Decker, an instructor in the course. “Pathologists want to learn how to utilize the imaging, and the radiologists want to understand the needs of the forensic pathologists.” The participants come from every country, Decker says. Other such short courses are taught in other parts of the world as well as in the United States. While there is no US board certification yet for forensic radiology, Decker expects that it could happen one day.

Forensic imaging has several advantages over conventional autopsy, which could facilitate its more widespread utilization. It is a viable option for those families who are opposed to autopsy for religious, cultural, or other reasons, Hines says. Forensic images presented in a courtroom are much more palatable to jurors than bloody photos from autopsies, Decker says. Another advantage is that high-resolution medical imaging and 3D scans can be used to obtain high-quality images. Radiation exposure is not a concern for the deceased, so high levels can be used if necessary to obtain quality images, Decker says. Because deceased patients don’t move, Hines adds. motion artifacts on the images are never an issue. Forensic imaging is also safer for the person performing the autopsy, as the risk of exposure to any uncertain pathogens the deceased may have had is eliminated, according to a study published on March 22 in Forensic Sciences Research. Ptak notes that during COVID, especially early in the pandemic, forensic imaging was preferred for that reason.

The laws in the United States and NAME policies currently dictate when an autopsy can and should be done. Forensic imaging is currently a supplement to the autopsy in the United States, Decker says. “Overseas places have used it as a screening tool to determine if any further work is needed, like an autopsy.”

Hines says she may be prejudiced, but she hopes that more radiologists become interested in forensic imaging and seek the needed training. “It is fascinating work, and it is my hope that motivated radiologists will figure out a way to incorporate this into their practice,” she says.

Decker says training more radiologists in forensics will allow them to collaborate more with the forensic pathologists, who are the medical representatives of the deceased. Radiologists can provide clinical information for their final reports, Decker says. “If there is further question, then the court would bring the radiologist in, but it is always the pathologist’s domain and jurisdiction.”

Beyond Radiology
Ptak has participated as a radiologist in a couple of criminal cases that have gone to trial and has helped forensic pathologists understand the imaging. This application of forensic radiology has been around for 20 to 30 years, he says, and he expects it will continue to be of interest to many radiologists. Forensic radiology has been used in child abuse cases. “It tells a lot of information about what’s happened to the child in a presentable way,” Ptak says.

One of the projects Ptak recently worked on with the Baltimore Office of the Chief Medical Examiner was creating an exact 3D-printed representation of evidence from CT scans of the deceased. “I created a model in a case of penetrating head injury that was used as evidence in the court trial,” he explains. “The model was created directly from data imported from the head CT.” An issue, Ptak says, is that these cases, child abuse/child death cases, gunshot wounds, and assaults, can be “highly emotional,” and it can be difficult for some to help create the evidence that is needed.

“Visualizations like this have proven to be one of the strengths of postmortem imaging and its utilization in court,” Decker says. “Forensic imaging has had a long, rich history in the US and abroad, but it has been growing in recent years,” she adds. Decker sees the growth of interest as “a positive because there is definitely a need for more radiologists to be trained in forensic imaging.”

— Beth W. Orenstein of Northampton, Pennsylvania, is a freelance medical writer and regular contributor to Radiology Today.