Postmortem CT angiography trumps autopsy in identifying cause of death
CT angiography could improve the quality of postmortem diagnosis, researchers reported in Radiology this week—but the tool isn’t often used in the autopsy room.
Advanced imaging techniques like computed tomography (CT) and MRI aren’t strangers to the sphere of postmortem analysis, lead author Silke Grabherr, MD, PhD, and colleagues wrote. In fact, they said, the short and affordable nature of CT and its contemporaries have pushed forensic pathology to take “an important step forward.”
“Compared with conventional autopsy, postmortem CT has several advantages which can lead to important improvements in both research and postmortem investigation,” Grabherr et al. wrote. And though some reasons for maintaining high-quality postmortem practices are obvious—like in criminal investigations—that data are also a vital quality control measure for surgical interventions and treatment at hospitals.
Still, despite CT’s efficacy in identifying cause of death, the method comes with two major pitfalls, the authors said. Low soft tissue contrast and poor visualization of the vascular system mean it’s more difficult to obtain clear images for clinical use. Because there’s a lack of blood flow, it’s hard to diagnose cardiovascular disease, a major cause of unexpected death in most developed countries.
But a technique known as postmortem CT angiography, or PMCTA, could be fixing those problems, the researchers said.
“The idea of the PMCTA is to simulate a postmortem circulation by establishing a postmortem perfusion of the vascular system,” Grabherr told the Radiological Society of North America. “Therefore, the heart is ‘replaced’ by a perfusion device, similar to the heart-lung machine that replaces the heart during surgery.”
Grabherr and her colleagues at nine European medical centers tested the method against CT without angiography and autopsy in 500 human bodies. The exams gave way to 18,654 findings in total, which were recorded and organized by anatomic structure and their relative importance in the forensic case.
Of the thousands of findings, the authors reported, autopsies identified 61.3 percent, postmortem CT identified 76 percent and CT angiography helped identify 89.9 percent. Angiography proved superior to autopsy in identifying skeletal lesions and vascular lesions—it identified 96 percent and 94 percent of lesions, respectively—and missed just 10 percent of forensically essential findings. Autopsy missed 23 percent.
“This method could, in many cases, be an alternative to invasive autopsy if such an opening of the body is not possible,” Grabherr said. “This offers new investigation possibilities, for example, in countries where a conventional autopsy is not accepted or in cases where family members can refuse it.”
The researchers said CT angiography produced the best results, but autopsy, postmortem CT and angiography all offer something the other two don’t.
“By combining autopsy and CT angiography, the reported number of findings can be increased, leading to a better postmortem examination,” Grabherr et al. wrote in Radiology. “If only imaging or autopsy can be applied, the choice depends on the investigated case and suspected findings.”
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.