Quantitative interpretation using ADC values for subjective MRI classification of neonatal hypoxic-ischemic encephalopathy

Abstract

Background

MRI-based classification of hypoxic–ischemic encephalopathy (HIE), particularly using diffusion-weighted imaging (DWI), remains susceptible to subjective bias in determining the presence or absence of diffusion restriction. Quantitative measures such as apparent diffusion coefficient (ADC) values may provide a more objective assessment of injury severity.

Purpose

To evaluate the depth and distribution of brain injury in neonatal HIE by quantitatively assessing regional ADC values across MRI pattern classifications, independent of subjective visual interpretation of DWI signal changes.

Materials and methods

Seventy-three consecutively enrolled full-term infants with HIE underwent brain MRI, and ADC values were measured at five predefined brain regions. Correlations between regional ADC values and MRI pattern groups were analyzed.

Results

Five MRI patterns were identified: normal, white matter injury (WMI), watershed (WS), basal ganglia/thalamus injury (BGT), and near total brain injury (nTBI). ADC distribution analysis demonstrated two principal findings: (1) no significant differences among the normal, WMI, and WS pattern groups; and (2) significantly lower ADC values in the nTBI group compared with the BGT group at all brain regions during the first week of life, and at the centrum semiovale during the second week.

Conclusion

Quantitative analysis revealed distinct ADC distribution differences between the BGT and nTBI patterns during the first and second weeks of life, indicating substantially more severe and widespread brain injury in the nTBI pattern.