Volumetric and anatomical MRI for hypoxic-ischemic encephalopathy: relationship to hypothermia therapy and neurosensory impairments

Abstract

Objective: To relate volumetric magnetic resonance imaging (MRI) findings to hypothermia therapy and neurosensory impairments.

Study design: Newborns > or =36 weeks' gestation with hypoxic-ischemic encephalopathy who participated in the National Institute of Child Health and Human Development hypothermia randomized trial at our center were eligible. We determined the relationship between hypothermia treatment and usual care (control) to absolute and relative cerebral tissue volumes. Furthermore, we correlated brain volumes with death or neurosensory impairments at 18 to 22 months.

Result: Both treatment groups were comparable before randomization. Total brain tissue volumes did not differ in relation to treatment assignment. However, relative volumes of subcortical white matter were significantly larger in hypothermia-treated than control infants. Furthermore, relative total brain volumes correlated significantly with death or neurosensory impairments. Relative volumes of the cortical gray and subcortical white matter also correlated significantly with Bayley Scales psychomotor development index.

Conclusion: Selected volumetric MRI findings correlated with hypothermia therapy and neurosensory impairments. Larger studies using MRI brain volumes as a secondary outcome measure are needed.

Conflict of interest statement

The authors have no conflicts of interest to disclose.

Figures

FIGURE 1. Representative example of brain volume segmentation and labeling methodology for an axial T2-weighted brain MRI

A. Unsegmented T2- weighted mid-brain MRI slice. B. Manual segmentation and labeling of smaller subcortical structures: 10-corpus callosum; 17-thalamus; 18-lenticular nucleus; 19-caudate nucleus C. Fully segmented mid-axial slice. Representative pixels were individually sampled from the lateral ventricles (light blue), subcortical white matter (white), and cortical gray matter (green) and segmented using a semi-automatic segmentation tool. Extra-axial CSF (cyan) spaces were sampled and labeled last, based on location and clear regional intensity differences.

FIGURE 1. Representative example of brain volume segmentation and labeling methodology for an axial T2-weighted brain MRI

A. Unsegmented T2- weighted mid-brain MRI slice. B. Manual segmentation and labeling of smaller subcortical structures: 10-corpus callosum; 17-thalamus; 18-lenticular nucleus; 19-caudate nucleus C. Fully segmented mid-axial slice. Representative pixels were individually sampled from the lateral ventricles (light blue), subcortical white matter (white), and cortical gray matter (green) and segmented using a semi-automatic segmentation tool. Extra-axial CSF (cyan) spaces were sampled and labeled last, based on location and clear regional intensity differences.

FIGURE 1. Representative example of brain volume segmentation and labeling methodology for an axial T2-weighted brain MRI

A. Unsegmented T2- weighted mid-brain MRI slice. B. Manual segmentation and labeling of smaller subcortical structures: 10-corpus callosum; 17-thalamus; 18-lenticular nucleus; 19-caudate nucleus C. Fully segmented mid-axial slice. Representative pixels were individually sampled from the lateral ventricles (light blue), subcortical white matter (white), and cortical gray matter (green) and segmented using a semi-automatic segmentation tool. Extra-axial CSF (cyan) spaces were sampled and labeled last, based on location and clear regional intensity differences.