Brain T1 in young children with sickle cell disease: evidence of early abnormalities in brain development

Measurement of tissue spin lattice relaxation time (T1) has been used to characterize brain development in healthy children. Here we report the first study of brain T1 in young children with sickle cell disease (SCD). The T1 in 10 tissue samples was measured by established techniques; 46 SCD patients under the age of 4 years were compared to 267 controls, including 55 well children under the age of 4 years. A model was developed to predict the relationship between age and brain T1 in controls, then we compared patient T1 to healthy normal T1. Most white matter and gray matter tissues in infant patients (<2 years old), had T1 values significantly higher than normal. For example, 15.0% of patient caudate T1 values were above the upper bound of the 95% confidence interval for controls, but only 2.5% of normal values are expected to be this high (p = 0.0003). Among infant patients, brain T1 was significantly higher than normal in every tissue (p < 0.01) except cortical gray matter. However, patient T1 values declined rapidly to values lower than normal by about age 4. Our findings imply that patients follow an abnormal developmental trajectory beginning early in infancy.