Autopsy examination of early miscarriages (<20 weeks’ gestation) can be technically challenging, with an associated error rate due to small size. Imaging is increasingly used to guide the autopsy process and post mortem MRI (PMMRI) at 1.5T shows excellent correlation with autopsy findings over 18gw / 500g bodyweight, however, its diagnostic accuracy is reduced below these thresholds. We have evaluated the use of Micro-CT, which has been used in animal imaging and industry for many years. We present a radiological / pathological correlation of a case from the first clinical use of micro-CT in perinatal autopsy practice, under an ethically approved study with full consent. A termination of pregnancy was performed at approximately 14gw for presumed sacrococcygeal teratoma. Standard CT and 1.5T PMMRI was non-diagnostic for every organ system. Following immersion of the fetus in potassium triiodide and formalin for 48 hours, a micro-CT scan was performed using a Nikon XTH225 micro-CT scanner, reconstructed using proprietary software (CT Pro 3D, Nikon Metrology) and post-processed using VG Studio MAX (Volume Graphics GmbH). Views of all organ systems were obtained that were used to guide subsequent unblinded autopsy. Micro-CT demonstrated multiple abnormalities, including amniotic membranes in contact with the fetal skin, multiple disruptions of the abdomen and limbs, and externalisation of internal organs including the kidneys and liver. These were confirmed at the subsequent autopsy and a final diagnosis of ADAM complex (amniotic deformity, adhesions, mutilations) was made. This case report demonstrates the potential of micro-CT to provide detailed PM imaging of entire fetuses whilst maintaining tissue integrity, allowing pre-autopsy identification of multiple congenital abnormalities in cases where 1.5T PMMRI and standard CT fail to achieve diagnostic resolutions.
IPR 2016 Conjoint Meeting & Exhibition