Extensive cerebral sinovenous thrombosis in a two-week old term infant with hypernatremic dehydration, lethargy, and a bulging fontanelle

Head CT (A) depicts acute venous thrombus as hyperdense signal involving sagittal and straight sinuses. Brain magnetic resonance venogram (B and C) depicts absent flow-related signal involving left transverse, entire superior sagittal, and straight sinuses. Acute clot appears as hyperintense signal (D) on sagittal T1-weighted sequences. Diffusion-weighted MRI sequences (E and F) show extensive acute ischemic changes in bilateral subcortical white matter, internal capsule, corpus callosum and thalamus (arrows). In addition, thalamic hemorrhage is present (asterisk).