Post-mortem cerebral magnetic resonance imaging T1 and T2 in fetuses, newborns and infants

Post-mortem magnetic resonance imaging (PM MRI) of brain is increasingly used in clinical practice; understanding of normal PM contrast to noise ratio (CNR), T1 and T2 values relaxation times is important for optimisation and accurate interpretation of PM MRI.MethodsWe obtained T1- and T2-weighted images at 1.5 T. In the first phase of the study, we calculated CNR in twelve brain regions in 5 newborn infants after death and compared this with CNR from 5 infants during life. In the second phase, we measured deep grey matter (GM) and white matter (WM) T1 post-mortem in 18 fetuses and T1 and T2 post-mortem 6 infants prior to autopsy.ResultsPhase I: post-mortem T1- and T2-weighted CNRs were lower in most brain regions than during life.Phase II: compared with in vivo, all post-mortem images lacked GM-WM contrast and had high T2-weighted WM signal intensity. Mean (SD) post-mortem T1 in white and deep gray matter were respectively 1898 (327) ms and 1514 (202) ms in fetuses (p > 0.05) and 1234 (180) ms and 1016 (161) ms in infants and newborns (p > 0.05). Mean (SD) post-mortem T2 was 283 (11) ms in WM and 182 (18) ms in deep GM in infants and newborns (p < 0.001).ConclusionsPost-mortem T1 and T2 values are higher than those reported from live cases. The difference between T1 values in GM and WM reduce after death.