Work

Hounsfield unit and gray-white matter ratio estimates in pediatric normal controls used in studies evaluating head computed tomography

Year: 2026

Type: article

Abstract: Head computed tomography (CT) plays a key diagnostic role in assessing anatomically visible cerebral injury, monitoring the development of edema and ischemia, and, in some diseases, assisting in the prediction of outcome. More specifically, after a cardiac arrest, head CT imaging will reveal the impact of global hypoxic-ischemic injury. In adults, some have shown that the gray-white matter ratio (GWR) calculated with Hounsfield units (HU) may be valuable for prognostication. Few studies have investigated their use in the pediatric population, and even fewer have considered age and maturation in their analyses. The objective of this study was to evaluate pediatric normal controls and report their HU and GWR values for use in future studies. Non-contrast head CT scans of children without neurological diseases were used. HU values were measured using predefined regions of interest and the circular dots method. GWR was estimated with 12 different formulas. Analyses were stratified by age (<2 and ≥ 2 years). We analyzed 42 scans. HU in the caudate nucleus, cortical gray matter, and brain parenchyma were lower in younger (n = 18) compared to older children ≥2 years (n = 24). No HU differences between the age groups were measured in the putamen, thalamus, and white matter. GWR calculated with basal ganglia (caudate nucleus + putamen) and cortical gray matter was lower in the younger group. Head CT measurements of HU and GWR change with age in children under 2 years. This feature was most relevant in gray matter areas. Future studies should evaluate which GWR formulas are most effective in assessing the severity of global hypoxic ischemic encephalopathy after cardiac arrest in the pediatric population.

Source: Neuroimage Reports

Authors: Kie Honjo, Geraldine Goco, Eva Ta, Suzanne Laughlin, Anne-Marie Guerguerian

Institutions: University of Toronto, Hospital for Sick Children

Language: English

Topic: Advanced MRI Techniques and Applications

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,160

Funders: Hospital for Sick Children, Garry Hurvitz Centre for Brain and Mental Health