Cover legend: Although cerebral white matter injury is the major cause of neurological disability in survivors of premature birth, defining the mechanisms of fetal ischemic brain injury has been an elusive problem because of the inherent difficulties of quantifying cerebral blood flow in utero. Quantitative three-dimensional reconstructions of fetal cerebral blood flow were achieved by determining the unique location of fluorescently labeled microspheres delivered into the microcirculation. Fluorescent microspheres are shown as colored dots within a reconstructed cut-away view of the cerebral surface and were injected as four discreet populations separable by color (red, basal flow; yellow, ischemia; green and blue, 15 and 60 min of reperfusion flow, respectively). Such approaches revealed that cerebral ischemia is necessary but is not sufficient to damage the developing cerebral white matter. For details, see the article by Riddle et al. in this issue (pages 3045–3055).