Background MRI is the neuroradiological investigation of choice for perinatal arterial ischaemic stroke (PAIS). However knowledge of the sequence of signal intensity (SI) change on conventional and diffusion weighted imaging (DWI) following PAIS is limited adding to the difficulty in accurate timing of the onset of injury.
Objective To analyze retrospectively PAIS evolution on serial conventional and DWI MR scans in symptomatic term-born infants.
Design/Methods We documented visually the patterns of T1, T2 and DWI signal intensity evolution after PAIS. A SI scoring system was used (−1 = lower, 0 = equal, 1 = higher) compared to the contralesional hemisphere. We also measured thalami/basal ganglia volume using Osirix software.
Results We analyzed 42 scans (<3 post-natal months, mean age first scan 4 days) from 21 term-born infants. Changes in SI in cortex and white matter (WM) over time within the region of stroke for T1 and T2-weighted images are shown in the fig. All DWI images showed high SI in WM until day 4 which fell to = /below the contralateral hemisphere by day 12. Thalamic volume was reduced compared to the non-lesional side for main (0.38) and posterior (0.67) branch middle cerebral artery PAIS from 2 post-natal months.