The effect of melatonin on brain metabolism and development after hypoxic-ischemic brain injury in the newborn rat evaluated by multimodal MR, 2014

Reduced supply of blood and oxygen to the brain around birth, known as perinatal hypoxic-ischemic (HI), may cause brain injury in newborns. In this project we investigated the effects of melatonin as a possible treatment that can reduce the damage. A ratmodel for HI injury (Vannucci-model) was used to compare the brain injury development of rats treated with melatonin (injections 0, 6 and 25 hours after injury) with rats without treatment (given injections with 5% DMSO or saline which were used as disolvants for melatonin). The rats were scanned with magnetic resonance 1, 7, 20 and 43 days after the HI injury with T2-weighted images, diffusion weighted images and diffusion tensor imaging.

Spin-Echo RARE T2-weighted images (day 1, 7, 20 and 43): RARE factor 8, effective TE 70 ms, TR 3500 ms, 4 or 8 averages, Field of View 20 x 20 mm2, acquisition matrix 160 x 160, 15 slices á 1 mm. Diffusion weighted images (day 1/P08): echo planar imaging (EPI) sequence with Stejskal-Tanner diffusion weighting using 6 b-values (100/200/400/600/800/1000 s/mm2) in 3 orthogonal directions, TE 30 ms, TR 3000 ms, 6 averages, Field of View 17.2 x 15 mm2, acquisition matrix 110 x 96, 9 slices á 1 mm. Diffusion tensor images (day 7, 20 and 43) using an EPI sequence with Stejskal-Tanner diffusion preparation with a b-value of 750 s/mm2 in 81 directions. 10 b0-images. TE 27.50 ms, TR 3000 ms, Field of View 19.25 x 13.65 mm2, acquisition matrix 110 x 78 reconstructed to 220 x 156, 12 axial slices of 0.75 mm thickness.