MRI opens door for minimally invasive autopsy alternative

MRI may offer a minimally invasive alternative to conventional autopsies, as a combination of MRI scans and other techniques, including blood and cerebrospinal fluid tests, was found to determine cause of death in fetuses and babies with accuracy nearly on par with standard autopsy, according to a study published online May 16 in The Lancet.

“Minimally invasive autopsy could increase the uptake of post-mortem examination if adequate resources are allocated,” wrote Sudhin Thayyil, PhD, of University College London, and colleagues, who noted that fetal autopsy consent rates in the U.K. had been declining, mainly due to parental objection.

The role of autopsy is important, they explained, not only to determine cause of death but in advancing medical research and knowledge.

The study, which was the first large-scale study to compare accuracy of minimally invasive autopsy techniques to full autopsy, involved analysis of 400 cases—277 of which were fetuses and 123 of which were babies or children. Whole-body MRI at 1.5T was conducted along with other minimally invasive post-mortem investigations, with conventional autopsy used as the reference standard, at two London centers between Marcy 1, 2007, and Sept. 30, 2011. A radiologist and pathologist blinded to conventional autopsy findings indicated whether the minimally invasive autopsy would have been sufficient.

Results showed the cause of death or major pathological lesion detected by minimally invasive autopsy was the same as full autopsy in 89.3 percent of cases. “Overall, concordance between minimally invasive autopsy findings and conventional autopsy was highest in fetuses and gradually decreased with increasing age in the pediatric population,” wrote the Thayyil and colleagues. They attributed the lower concordance in children to pneumonia and myocarditis that went undetected on MRI.

Post-mortem MRI was most accurate in the detection of cerebral, cardiac and renal abnormalities, added the authors.

Review by the radiologist and pathologist showed that 41 percent of the full autopsies might not have been needed as the minimally invasive technique would have been sufficient. In these cases, concordance between the minimally invasive autopsy and full autopsy reference standard was greater than 99 percent.

“Close engagement of parents is important in such a process, and contrary to popular belief, bereaved parents often view this involvement positively,” wrote the authors.

In a linked comment, Corinne Fligner, MD, and Manjiri Dighe, MD, of the University of Washington Medical Center in Seattle wrote that the work from Thayyil et al could serve as the starting point for adjusting autopsy processes. “Crucial to success of an integrated post-mortem diagnostic program will be clear performance standards, regular audits, physician training, and sufficient and stable funding to attract, train, and retain specialists and provide state-of-the-art resources for radiology and pathology.”