Frequency, Extent, and Correlates of Superficial Siderosis and Ependymal Siderosis in Premature Infants with Germinal Matrix Hemorrhage: An SWI Study

BACKGROUND AND PURPOSE: Germinal matrix intraventricular hemorrhage is a common complication of prematurity. An underrecognized complication of germinal matrix intraventricular hemorrhage is superficial siderosis, and the clinical consequences of superficial siderosis are not well-known. We aimed to investigate the prevalence, anatomic distribution, and severity of superficial siderosis and ependymal siderosis in premature infants with germinal matrix intraventricular hemorrhage using SWI. MATERIALS AND METHODS: In this retrospective study, we included 88 patients across all grades of germinal matrix intraventricular hemorrhage who underwent MR imaging at term-equivalent age. Images were evaluated for the presence, distribution, and severity of superficial siderosis and ependymal siderosis. Univariate and multivariate logistic regression analyses were performed to determine factors associated with superficial siderosis and ependymal siderosis. The agreement among T1, T2, and SWI sequences was examined. RESULTS: Seventy-two patients had brain stem superficial siderosis, and 79 patients had ependymal siderosis. The presence, extent, and severity of superficial siderosis and ependymal siderosis were closely related to the grade of germinal matrix intraventricular hemorrhage and intraventricular hematoma volume. Brain stem superficial siderosis had a stronger correlation with intraventricular hemorrhage than with cerebellar hemorrhage. Compared with SWI, T1 and T2 sequences detected only small proportions of patients with superficial siderosis (12.5% and 6.9%, respectively). CONCLUSIONS: The incidence of superficial siderosis and ependymal siderosis is very high in preterm infants with germinal matrix intraventricular hemorrhage when assessed by SWI at term-equivalent age. The presence and extent of superficial siderosis and ependymal siderosis are closely related to germinal matrix intraventricular hemorrhage grade and intraventricular hematoma volume. Additional prospective studies using SWI are needed to clearly determine the clinical consequences of germinal matrix intraventricular hemorrhage with superficial siderosis and ependymal siderosis.