Concordance and Association of Kidokoro MRI Scores at 32 and 40 weeks post-menstrual age with Neurodevelopmental Outcomes in Very Preterm Infants

Background and purpose: Early identification of neurodevelopmental risk in very preterm infants is critical for timely intervention. The Kidokoro MRI scoring system offers a semi-quantitative approach to evaluating brain abnormalities. This study aimed to assess the agreement of Kidokoro scores obtained in the same infants at 32- and 40-weeks postmenstrual age, and their association to cognitive, language, and motor outcomes at 24 months corrected age. Materials and methods: A cohort of 187 very preterm infants (median 28+5weeks gestational age; 55% male) underwent structural MRI at two timepoints: Early (median 32+2weeks) and Term-Equivalent Age (median 40+5weeks), using 3 T scanners. Scans were scored independently using a modified version of the Kidokoro system. Bland-Altman analysis assessed agreement between Early and term equivalent age scores. Neurodevelopmental outcomes were assessed at 24 months using the Bayley-III. Multivariable linear regression models evaluated the predictive value of MRI scores, adjusting for sex, gestational age, birthweight centile, and socioeconomic status. Results: Early MRI scores were consistently higher than term equivalent age scores (mean difference 1.9; 95%CI: 1.6-2.2), with white matter scores showing the largest discrepancy (mean difference 1.68; 95%CI: 1.46-1.90), primarily due to the "myelination delay" item. Excluding this item reduced the difference to 0.32 (95%CI: -0.01 to 0.64). Early and TEA Kidokoro global brain abnormality score (GBAS) were negatively associated with Bayley-III cognitive and motor, but not language scores. Higher GBAS were associated with lower cognitive (Early: β= -0. 67, 95%CI: -1.23 to -0.11; Partial R2=0.03; TEA: β= -0.60 95%CI: -1.15 to -0.06, Partial R2=0.03) and motor scores (Early: β= -1.04, 95%CI: -1.67 to -0.41, Partial R2=0.06; TEA: β= -1.18, 95%CI: -1.78 to -0.58, Partial R2=0.08). Reduction in GBAS from Early to TEA correlated with higher motor scores (β=1.02, 95%CI: 0.03 to 2.02, Partial R2=0.02). White matter abnormalities were linked to poorer motor outcomes at both timepoints. Conclusions: Kidokoro scores at early and term-equivalent timepoints are associated with neurodevelopmental outcomes at 24 months. Global abnormalities and white matter scored at either timepoints, or their longitudinal changes are significantly linked to motor outcomes. Refinement of scoring system for the early assessment may enhance clinical utility. The authors declare no conflicts of interest related to the content of this article.