Technical note: sonography through the posterior fontanelle in diagnosing neonatal intraventricular hemorrhage.

Studies comparing sonographic and autopsy findings have shown diagnostic errors in 8-34% of cases of neonatal intraventricular hemorrhage (IVH) [1, 2]. The main reasons cited for these inaccuracies are blood missed in normal-sized ventricles, a very small amount of blood (usually in the occipital horns), or a large normal choroid plexus mistaken for hemorrhage. Because overlooked IVH tends to be found in the occipital horns at autopsy, and sonography through the posterior fontanelle gives excellent visualization of the occipital horns, posterior fontanelle scanning may offer advantages over anterior fontanelle scanning alone. This is not a new concept, as posterior fontanelle scanning for IVH was described in the early 1980s [3, 4]; however, it has received scant attention since then.