Cerebral arterial lumens are enlarged in children and young adults with sickle cell disease compared to peers.

Children with sickle cell disease (SCD) may develop large vessel narrowing, but studies suggest vessels may also be enlarged, possibly related to increased cerebral blood flow (CBF). We used MRI to investigate whether the cross-sectional total inflow vessel luminal area (TIVLA) proximal to the circle of Willis (carotid arteries + basilar artery) would be increased in SCD compared to age- and sex-matched peers after adjusting for CBF. Across 36 children with SCD (19 female, median age 10.7 [8.0-14.5] years and 43 controls (26 female, median age 12.7 [9.2-18.2] years) matched by age ( = 0.13) and sex ( = 0.50), the median TIVLA in the SCD group (35.9 mm [30.7, 39.5]) was larger than controls (30.5 mm [27.8, 35.4], = 0.002). In a mixed model including age, sex, hemoglobin, CBF, SCD status, and an interaction between hemoglobin and SCD status, CBF (β = 0.11, CI 0.02-0.20, = 0.02), SCD (β = 28.02, CI 5.62-50.42, = 0.015), and the interaction between SCD and hemoglobin (β = -2.48, CI -4.49 to -0.47, = 0.018) were all significantly associated with increased TIVLA. Notably, TIVLA as a measure of arterial lumens is larger in children with SCD, even after adjusting for CBF in the mixed model. This implies disease-specific normative values may be needed to detect early vasculopathy.