Newborn with a full fontanelle

US of HSV-1 / herpes simplex virus-1 encephaliti
Coronal US of the brain (above) shows a round echogenic lesion in the left fronto-parietal region. Axial CT without contrast of the brain (below) shows the lesion to be high density with surrounding low density edema and felt to represent intraparenchymal hemorrhage.

The diagnosis was herpes simplex virus-1 encephalitis.