Practical approach to measuring vessels and reporting z-scores in children

Heart size and vessel diameters naturally increase with a child's growth, development, and needs. Measuring the size of blood vessels and tracking their growth have become a common practice among pediatric imaging specialists. Practitioners use tools like z-scores to standardize measurements against reference values that account for age, sex, and/or body size and habitus and help determine if vascular measurements deviate from what is expected in a healthy population. In this article, we review measurement techniques of significant vascular regions of interest in children covering "how to measure," "where to measure," and "sources of measurement errors." We also go over the concept of reporting z-scores in children with a review of the available literature and commonly used pediatric z-score calculators.