Diagnostic accuracy of postmortem ultrasound vs postmortem 1.5‐T MRI for non‐invasive perinatal autopsy

Abstract

Objectives To determine the diagnostic accuracy of postmortem magnetic resonance imaging (PM‐MRI) and postmortem ultrasound (PM‐US) for perinatal autopsy in the same patient cohort, and to determine whether PM‐US can provide the same anatomical information as PM‐MRI. Methods In this prospective, 5‐year (July 2014–July 2019) single‐center study, we performed 1.5‐T PM‐MRI and PM‐US in an unselected cohort of perinatal deaths. The diagnostic accuracies of both modalities were calculated, using autopsy as the reference standard. As a secondary objective, the concordance rates between the two imaging modalities for the overall main diagnosis and for five anatomical regions (brain, spine, thorax, heart and abdomen) were calculated. Results During the study period, 136 cases underwent both PM‐US and PM‐MRI, of which 88 (64.7%) also underwent autopsy. There was no significant difference in the rates of concordance with autopsy between the two modalities for overall diagnosis (PM‐US, 86.4% (95% CI, 77.7–92.0%) vs PM‐MRI, 88.6% (95% CI, 80.3–93.7%)) or in the sensitivities and specificities for individual anatomical regions. There were more non‐diagnostic PM‐US than PM‐MRI examinations for the brain (22.8% vs 3.7%) and heart (14.7% vs 5.1%). If an ‘imaging‐only’ autopsy had been performed, PM‐US would have achieved the same diagnosis as 1.5‐T PM‐MRI in 86.8% (95% CI, 80.0–91.5%) of cases, with the highest rates of agreement being for spine (99.3% (95% CI, 95.9–99.9%)) and cardiac (97.3% (95% CI, 92.4–99.1%)) findings and the lowest being for brain diagnoses (85.2% (95% CI, 76.9–90.8%)). Conclusion Although there were fewer non‐diagnostic cases using PM‐MRI than for PM‐US, the high concordance rate for overall diagnosis suggests that PM‐US could be used for triaging cases when PM‐MRI access is limited or unavailable. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Diagnostic Evaluation of the Posterior Fossa with Antenatal and Post-Mortem MRI: An Unfolded View

“…Similarly, Shruthi et al [19], found that PMMRI was comparable and even superior to CA for PF abnormalities. Authors also found that PMMRI can provide additional diagnostic information of the fetal nervous system and can be an acceptable alternative to CA when this is refused by the parents [11,15,17,19].…”

“…Different imaging modalities have been used to assess the fetus in the PM period. The US offers easy access and affordability, but its limiting factors include overlapping cranial sutures and brain maceration [15]. Microfocus computed tomography (CT) has shown good results for fetuses \ 20 weeks of gestational age (GA) [16][17][18].…”

“…PMMRI is the most researched imaging technique, with a fairly high diagnostic accuracy. It has been useful even with fetal maceration, where CA may fail [11,15,17,19].…”

Less‐invasive autopsy for early pregnancy loss

“…41,[45][46][47][48][49] It should also be noted that identifying abnormalities in early gestation through CA also remains challenging. 47,48,[50][51][52][53][54][55][56][57] Several terms are commonly used to describe the different post-mortem approaches towards diagnosis, and it is important to understand the investigations each term refers to and what can be achieved (Table 1).…”

A pragmatic evidence-based approach to post-mortem perinatal imaging

“…When the imaging is of diagnostic quality, ultrasound has been reported to have a similar accuracy to both 1.5 T [ 25 ] and 3 T MRI [ 26 ], with an estimated overall sensitivity of 73% and specificity 97% (based on a systematic review of 455 perinatal losses)[ 27 ]. The highest sensitivity rates were found for brain imaging (84%) and lowest for cardiothoracic abnormalities (51%).…”