Imaging Meets the Forensic Files

Postmortem imaging is revolutionizing death investigation and research, with postmortem CT (PMCT) now regularly used to investigate deaths in both the forensic and clinical settings.

“PMCT is a force multiplier, enabling rapid triage of cases, unbiased and unaltered documentation, and a permanent archive,” said Jamie Elifritz, MD, a diagnostic radiologist who serves as chief medical officer for the Forensic Radiology Group. “It increases throughput and lowers the threshold to investigate by making the process faster and less invasive.”

In forensics, PMCT is useful for detecting and localizing subtle fractures, air and fluid collections, and foreign bodies such as bullet fragments, providing a 3D ‘roadmap’ for the forensic pathologist. On the clinical side of the equation, it allows doctors to compare clinical diagnoses made during life with the actual findings at death.

PMCT can also check the position and integrity of devices inside the body after death, helping investigators confirm whether device placement contributed to a complication or death.

“In short, PMCT provides a way to ‘audit’ the accuracy of diagnoses and treatments after death,” explained Kalpana Kanal, PhD, chief of diagnostic physics at the University of Washington (UW) in Seattle.

Imaging Before Incision

PMCT can also complement full autopsy. “Because PMCT provides a full-body, permanent, and shareable record before any incision is made, it can help pathologists make informed decisions about which cases require full autopsy,” said J. Matthew Lacy, MD, chief medical examiner at the King County Medical Examiner Office in Seattle.

“PMCT can help increase the quality of death investigations by offering a non-invasive, faster, and more acceptable alternative to traditional autopsy,” added David Zamora, MS, a medical physicist at UW.

When full autopsy is indicated, PMCT findings can be used to guide dissection and document evidence. “PMCT can inform a more targeted dissection, which saves time and, in certain cases such as trauma, mass disasters or when families object to autopsy, can serve as a partial or alternative approach to traditional autopsy,” Dr. Kanal noted.

How Imaging Adds Value to Standard Autopsy

Despite its many strengths, PMCT does have limitations. For instance, due to postmortem changes in tissue and the inability to routinely give intravenous contrast, it can miss soft tissue pathology.

As a result, conventional autopsy remains the gold standard. “While PMCT is unlikely to entirely replace autopsy, integrating it into a collaborative program between the medical examiner’s office and radiology adds substantial value to forensic and medicolegal death investigations,” said Jonathan Medverd, MD, chief of radiology at the UW Harborview Medical Center.

To illustrate, Dr. Medverd noted how, in homicide cases, PMCT can reveal additional details or offer different perspectives than the standard autopsy. These details can be invaluable in explaining injuries to juries with little medical background, and they can make the evidence less emotionally upsetting.

“For hospital deaths, presenting antemortem CT scans can be more informative than autopsy when therapeutic interventions have altered disease appearance,” Dr. Medverd explained. “In addition, 3D PMCT renderings may address concerns that autopsy photographs are overly prejudicial, enhancing their probative value in judicial proceedings.”