A 6-month old male imaged for macrocephaly

T1 (panel A) and T2 (panel B)-weighted MRI images show enlargement of the subarachnoid spaces, establishing the diagnosis of benign extra-axial fluid of infancy. Follow-up T1 (panel C) and T2 (panel D)-weighted images reveal subdural hematoma within the enlarged spaces. The child was completely asymptomatic from this and required no treatment. The areas of hematoma resolved spontaneously.