T2 relaxometry in the extremely-preterm brain at adolescence

Abstract

Survival following very preterm birth is associated with cognitive and behavioral sequelae, which may have identifiable neural correlates. Many survivors of modern neonatal care in the 1990s are now young adults and the evolution of MRI findings into adult life has rarely been evaluated. We have investigated a cohort of 19-year-old adolescents without severe impairments born between 22 and 26 weeks of gestation in 1995 (extremely preterm: EP). Using T2 data derived from magnetic resonance imaging we investigate differences between the brains of 46 EP participants (n = 46) and the brains of a group of term-born controls (n = 20). Despite EP adolescents having significantly reduced gray and white matter volumes, the composition of these tissues, assessed by both single and multi-component relaxometry, appears to be unrelated to either preterm status or gender. This may represent either insensitivity of the imaging technique or reflect that there are only subtle differences between EP subjects and their term-born peers.

Somatosensory function and pain in extremely preterm young adults from the UK EPICure cohort: sex-dependent differences and impact of neonatal surgery

“…2 ) and no difference in tissue composition using T2 relaxometry has been reported in this cohort. 37 Lower amygdala volume sex-dependently correlated with reduced thermal sensitivity (HPT, CPT, and cold pressor tolerance) in males, but increased sensitivity in females ( Supplementary Table 6 ). In EP participants, amygdala volume was negatively correlated with HPT in males (r s =–0.43, P =0.03) but positively in females (r s =0.44, P< 0.01; Fig.…”

“… 51 Importantly for evaluation of future risk, alterations in amygdala volume and connectivity also predicted the transition from acute to chronic back pain in adults. 52 After preterm birth, alterations in brain structure and connectivity persist beyond adolescence, 2 , 37 and functional correlates include reduced cognitive ability 53 and poorer psychosocial functioning. 54 More specifically, differences in amygdala volume and connectivity influenced fear processing and emotion recognition after preterm birth.…”

Current Methods of Magnetic Resonance for Noninvasive Assessment of Molecular Aspects of Pathoetiology in Multiple Sclerosis

“…This is most likely because of the influence of WM tissue water content (8–13% [ 193 ]), which moreover increases during various pathologic processes (i.e., inflammation, gliosis, edema, axonal demyelination) [ 17 ]. Furthermore, the decay of the MR visible proton signal in multi-echo T 2 relaxation measurements is in general multiexponential, consisting of a very long relaxation associated with the free water in cerebrospinal fluid (T 2 relaxation time >2000 ms), intermediate relaxation attributable to intra- and extracellular water (T 2 relaxation time ~80 ms), and short relaxation typical for the water trapped between the myelin bilayers (T 2 relaxation time ~30 ms) [ 27 , 225 ]. For in vivo tissue examination, a monoexponential fit of the signal decay is preferably used, resulting in a much easier evaluation of alterations in the brain tissue [ 193 , 199 ].…”

Translational studies identify long-term impact of prior neonatal pain experience

“…2C) [198]. Longitudinal evaluation at 19 years in the EPICure cohort, encompassing a range of outcomes to assess cognitive, behavioral and health outcomes [49] has recently been completed, and data from current pain and a comprehensive QST protocol is currently being analyzed.…”