Signa ovation excite

Brain scans were performed using a 0.35-T Signa Ovation Excite MRI scanner (General Electric, Milwaukee, USA). Two radiologists, unaware of each other’s readings and each patient’s retinopathy status and clinical outcome, interpreted each MRI scan. Brain swelling was graded for severity on the basis of pre-specified criteria [12 (link)]. Overall brain swelling was scored on the basis of the appearance of the cerebral hemispheres on a scale from 1 to 8, with a score of 1 indicating marked atrophy, 2 mild atrophy, 3 normal brain size, 4 slight swelling, 5 mild swelling, 6 moderate swelling, 7 substantial swelling with diffuse sulcal and cisternal effacement but no evidence of herniation, and 8 sulcal and cisternal effacement with evidence of herniation [12 (link)]. Scores of 7 and 8 were pre-specified as severe brain swelling because the radiologists considered these scores to indicate a life-threatening condition [12 (link)]. In this study, brain swelling was defined as follows: score of ≤ 3: normal brain size; scores of 4–5: mild swelling; score of 6: moderate swelling; scores of 7–8: severe swelling.

Neuroimaging was used to assess brain swelling with a 0.35T Signa Ovation Excite MRI scanner (GE Healthcare, Milwaukee, Wisconsin). The scans were read independently by two radiologists as previously reported [5 (link), 6 (link), 22 (link)]. Patient brain volume score was assigned based on a consensus interpretation of both radiologists. Brain volume was measured using a 1–8 scoring system, 1 and 2 indicating atrophy, 3-normal brain volume, 4-slightly increased brain volume, 5-mildly increased brain volume, 6-moderately increased brain volume, defined as loss of some sulcal markings, 7-moderately/severely increased brain volume with diffuse sulcal and cisternal effacement universally evident but without herniation present, and 8-severely increased brain volume with the findings of 7 and with evidence of herniation.