Perinatal Subdural and Parenchymal Hematomas, secondary to thrombocytopenia

4-day-old female born at 38 weeks gestation with infantile spasm and lethargy. The images demonstrate numerous T1-hyperintense, T2-hypointense hemorrhages with signal loss on the susceptibility weighted images. The hemorrhages are both parenchymal and subdural. The subdural collections demonstrate dependent hematocrit levels on the T2-weighted images. There is also intraventricular hemorrhage on the atria and occipital horns bilaterally. The patient had a platelet count less than 20,000 when evaluated. The signal characteristics are compatible with early subacute hemorrhage, approximately 3-10 days old. Early subacute hemorrhage represents intracellular methemoglobin. On lysis of the red blood cells and the development of extracellular methemoglobin, the late subacute hemorrhage will be hyperintense on both the T1 and T2-weighted images.