Sonographic appearance of the torcular Herophili.

The sonograms of 12 infants aged 2 days to 7 months were evaluated to determine if the torcular Herophili could be demonstrated routinely on cranial sonography. Sonography, which was performed for a variety of indications (prematurity, seizures, hydrocephalus, sepsis, congenital anomalies, and subarachnoid hemorrhage) demonstrated the torcular Herophili in all cases. It appeared as a variable-sized, anechoic, and triangular or elongated structure inferior to the occipital lobes, posterior to the cerebellum, and just inside the cranial vault. Correlation with computed tomographic scans was available in four patients. A detailed description of the normal anatomy of the torcular Herophili is provided. Knowledge of the variable sonographic appearance of the torcular Herophili is important to distinguish it from a pathologic entity.