MR Line-Scan Diffusion-Weighted Imaging of Term Neonates with Perinatal Brain Ischemia

Patient 8. Neonate of estimated 39-week gestational age with a lacerated, prolapsed umbilical cord.

A, Axial T2-weighted fast spin-echo image (3200/85/1), with an echo train length of 8, obtained at 3 days of life at the level of the basal ganglia shows T2 shortening (hypointensity) in the posterior putamen and ventrolateral thalamus bilaterally (compare with fig 1A). The cortical ribbon is indistinct.

B, ADC map (1520/62.5/1), with a b max of 750 s/mm², obtained at 3 days of life at a corresponding level shows decreased diffusion (hypointensity) in the ventrolateral thalami (arrows) and, to a lesser extent, in the occipital lobe gray matter (arrowheads). The hyperintensity of the frontal lobe white matter is due to the high diffusion that is normally present in the white matter of neonates.

C, Axial T2-weighted image obtained at 3 days of life above the lateral ventricles shows loss of the cortical ribbon in the frontal and parietal lobes and mild white matter hyperintensity.

D, ADC map obtained at 3 days of life at the same level shows pathologically decreased diffusion in the left perirolandic white matter (arrows). Decreased diffusion was apparent in the right perirolandic white matter at other levels (not shown). Note that the white matter of the centrum semiovale apart from the perirolandic white matter does not have decreased diffusion.

E, Axial T2-weighted image obtained at 7 days of life shows marked hypointensity in the posterior putamen/ventrolateral thalami, posterior thalamic hyperintensity, and diffuse white matter hyperintensity.

F, ADC map obtained at 7 days of life at a corresponding location shows heterogeneously decreased ADCs (hypointensity) within the thalami and markedly decreased ADCs throughout the occipital lobe white matter.

G, Axial T2-weighted image obtained at 7 days of life shows marked T2 prolongation within the white matter.

H, ADC map obtained at 7 days of life shows decreased ADCs within the white matter.

Patient 6. Neonate of estimated 41-week gestational age with placental abruption, no spontaneous respirations, and seizures. Life support was withdrawn at 23 hours of life.

A, Axial T2-weighted fast spin-echo image (3200/85/1), with an echo train length of 8, obtained at 18 hours of life shows no brain abnormality. Small bilateral occipital subdural hematomas are present.

B, Trace LSDI image (1520/62.5/1), with a b max of 750 seconds/mm², shows decreased diffusion (hyperintensity) bilaterally in the basal ganglia and thalami. Note that the frontal and parietal lobe cortex and white matter appear to have normal diffusion. Pathologic analysis revealed diffuse infarction was present throughout the brain.