Elevated cerebral blood volume contributes to increased FLAIR signal in the cerebral sulci of propofol-sedated children.

BACKGROUND AND PURPOSE: Hyperintense FLAIR signal in the cerebral sulci of anesthetized children is attributed to supplemental oxygen ( fractionof inspired oxygen) but resembles FLAIR hypersignal associated with perfusion abnormalities in Moyamoya diseaseand carotid stenosis. We investigated whether cerebral perfusion, known to be altered by anesthesia, contributes to diffuse signal intensity in sulci in children and explored the relative contributions of supplemental oxygen, cerebral perfusion, and anesthesia to signal intensity in sulci. MATERIALS AND METHODS: Supraventricular signal intensity in sulci on pre- and postcontrast T2 FLAIR images of 24 propofol-sedated children (6.20 ± 3.28 years) breathing supplemental oxygen and 18 nonsedated children (14.28 ± 2.08 years) breathing room air was graded from 0 to 3. The Spearman correlation of signal intensity in sulci with the fractionof inspired oxygenand age in 42 subjects, and with dynamic susceptibility contrast measures of cortical CBF, CBV, and MTT available in 25 subjects, were evaluated overall and compared between subgroups. Factors most influential on signal intensity in sulci were identified by stepwise logistic regression. RESULTS: CBV was more influential on noncontrast FLAIR signal intensity in sulci than the fractionof inspired oxygenor age in propofol-sedated children (CBV: r = 0.612, P = .026; fractionof inspired oxygen: r = −0.418, P = .042; age: r = 0.523, P = .009) and overall (CBV: r = 0.671, P = .0002; fractionof inspired oxygen: r = 0.442, P = .003; age: r = −0.374, P = .015). MTT (CBV/CBF) was influential in the overall cohort ( r = 0.461, P = .020). Signal intensity in sulci increased with contrast in 45% of subjects, decreased in none, and was greater ( P r = .600, P = .002). CONCLUSIONS: Elevated cortical CBV appears to contribute to increased signal intensity in sulci on noncontrast FLAIR in propofol-sedated children. The effects of propofol on age-related cerebral perfusion and vascular permeabilitymay play a role.