Abstract TMP113: Non-invasive Estimate of Intracranial Arterial Luminal Diameter in Children

Abstract

Background: Growth of the intracranial arteries facilitates the rapid increase in cerebral growth in the first 2 decades of life. In the age of cerebral endovascular treatment, many questions arise in the pediatric cohort regarding the safety and efficacy of these therapeutic approaches. Small arterial diameter may influence treatment selection in the very young, but to date little normative data is available to define vascular growth in infants and children. Methods: Subjects in this single-institution, retrospective cohort study were identified by MRI brain imaging keyword query as “normal” with age 0-18 years old at the time of the study. Medical records were reviewed to capture weight, length, and head circumference and exclude cerebrovascular or connective tissue disease risk factors. MRI T2-weighted images were measured to calculate the head circumference and arterial diameter in axial and coronal planes. A growth curve was created from the head circumferences and intracranial artery diameters to compare luminal caliber to age, sex and recorded growth parameters. Results: 317 subjects (170 female, 147 male) are included in the analysis. Luminal diameter was observed to increase rapidly in all arterial segments over the first 3 years of life. Compared to weight and length, head circumference most closely correlated with arterial size. Head circumference growth is most rapid during the first 3 years, tracking closely with the rate of luminal growth. An example relationship between arterial diameter and head circumference is shown in Figure 1. Conclusions: This is the largest cohort of cerebral arterial luminal growth in childhood. We show that arterial diameter can be measured non-invasively on MRI brain and correlated to routinely measured growth parameters. A better understanding of normal arterial growth is essential to our treatment of cerebrovascular disease in children.