PURPOSE: The aim of this study was to determine T2* values for the fetal brain in utero and to compare them with previously reported values in preterm and term neonates. Knowledge of T2* may be useful for assessing brain development, brain abnormalities, and for optimizing functional imaging studies. METHODS: Maternal respiration and unpredictable fetal motion mean that conventional multishot acquisition techniques used in adult T2* relaxometry studies are not practical. Single shot multiecho echo planar imaging was used as a rapid method for measuring fetal T2* by effectively freezing intra-slice motion. RESULTS: T2* determined from a sample of 24 subjects correlated negatively with gestational age with mean values of 220 ms (±45) for frontal white matter, 159 ms (±32) for thalamic gray matter, and 236 ms (±45) for occipital white matter. CONCLUSION: Fetal T2* values are higher than those previously reported for preterm neonates and decline with a consistent trend across gestational age. The data suggest that longer than usual echo times or direct T2* measurement should be considered when performing fetal fMRI to reach optimal BOLD sensitivity.
PURPOSE: The aim of this study was to determine T2* values for the fetal brain in utero and to compare them with previously reported values in preterm and term neonates. Knowledge of T2* may be useful for assessing brain development, brain abnormalities, and for optimizing functional imaging studies. METHODS: Maternal respiration and unpredictable fetal motion mean that conventional multishot acquisition techniques used in adult T2* relaxometry studies are not practical. Single shot multiecho echo planar imaging was used as a rapid method for measuring fetal T2* by effectively freezing intra-slice motion. RESULTS: T2* determined from a sample of 24 subjects correlated negatively with gestational age with mean values of 220 ms (±45) for frontal white matter, 159 ms (±32) for thalamic gray matter, and 236 ms (±45) for occipital white matter. CONCLUSION: Fetal T2* values are higher than those previously reported for preterm neonates and decline with a consistent trend across gestational age. The data suggest that longer than usual echo times or direct T2* measurement should be considered when performing fetal fMRI to reach optimal BOLD sensitivity.
Authors: Anna I Blazejewska; Sharmishtaa Seshamani; Susan K McKown; Jason S Caucutt; Manjiri Dighe; Christopher Gatenby; Colin Studholme Journal: Magn Reson Med Date: 2016-10-03 Impact factor: 4.668
Authors: Jana Hutter; Paddy J Slator; Laurence Jackson; Ana Dos Santos Gomes; Alison Ho; Lisa Story; Jonathan O'Muircheartaigh; Rui P A G Teixeira; Lucy C Chappell; Daniel C Alexander; Mary A Rutherford; Joseph V Hajnal Journal: Magn Reson Med Date: 2018-09-21 Impact factor: 4.668