MRI Score Ability to Detect Abnormalities in Mild Hypoxic-Ischemic Encephalopathy

Background: Magnetic resonance imaging (MRI) scores have been well validated in moderate/severe hypoxic-ischemic encephalopathy (HIE). Infants with mild HIE can have different patterns of injury, yet different scores have not been compared in this group of infants. Our objective was to compare the ability of three = MRI scores to detect abnormalities in infants with mild HIE, and infants with moderate/severe HIE were included for comparison. Methods: This is a single-center prospective cohort study of infants ≥36 weeks’ gestation with HIE born at a level III neonatal intensive care unit from 2017 to 2019. All infants with HIE underwent an MRI, but only infants with moderate/severe HIE underwent therapeutic hypothermia. At least two experienced MRI readers who were unaware of all clinical variables independently assigned three scores (Barkovich, NICHD NRN, and Weeke). Results: A total of 42 newborns with varying HIE severity underwent MRI on day five of life. In the overall cohort, abnormalities were reported in three (7%) infants using the Barkovich, in 10 (24%) using the NICHD NRN, and in 24 (57%) using the Weeke score. Agreement was excellent for each score: Barkovich score (k = 1.0), NICHD NRN (k = 0.92), and Weeke score (k = 0.9). Conclusions: Subtle injury due to mild HIE was detected with the highest frequency using the Weeke score, while inter-rater reliability was excellent for all three scores. These findings suggest that infants with mild HIE and subtle MRI abnormalities may benefit from detailed scoring systems, which is important for studies investigating the benefit of hypothermia in mild HIE.