CLINICAL REPORT PEDIATRICS Comparison of Spin-Echo T1- and T2-Weighted and Gradient-Echo T1-Weighted Images at 3T in Evaluating Very PretermNeonates at Term-Equivalent Age

SUMMARY: Term-equivalent imaging can assess myelination status in very preterm infants (30 weeks ’ gestational age at birth). How-ever, myelination assessment has yet to be compared among GRE-T1WI, SE-T1WI, and SE-T2WI at 3T. We aimed to compare the rates of myelination among those 3 sequences in 11 very pretermneonateswho underwent 3TMR imaging at term-equivalent age and subsequently had normal neurologic development. On each sequence, 2 neuroradiologists individually assessed 22 structures. SE-T2WI depicted a higher myelination rate (present in 58.2%–66.4 % of all structures) than either GRE-T1WI (51.6%–63.9%) or SE-T1WI (20.5%–38.5%), while GRE-T1WI had the highest interobserver agreement (, 0.56; P .0001). Myelination was present in 90%–100 % of patients within the corpus callosum splenium, DSCP, ICP, lateral lemniscus, and spinal tract/nucleus of cranial nerve V on SE-T2WI, and in the DSCP, ICP, lateral lemniscus, medial lemniscus, pyramidal decussation, PLIC, and superior cerebellar peduncle on GRE-T1WI, occurring in similar structures as previously shown at 1.5T and 1T. However, it is not clear whether these findings represent true myelination versus precursors to myelination. ABBREVIATIONS: DSCP decussation of superior cerebellar peduncles; GRE gradient-recalled echo; ICP inferior cerebellar peduncle; PLIC posterior limb of the internal capsule, SE spin-echo Term-equivalent brain MR imaging has been used as a predic-tor of late outcome in preterm infants in many centers, though it remains a controversial part of early clinical manage-ment.1,2 One reason some have advocated an initial MR imagin