Cephalhaematoma Mimicking an Extradural Haematoma due to MirrorImage Artifact on Sonography in a Term Neonate: A Case Report

Abstract

Cephalhaematomas and subgaleal haematomas are among the most common birth injuries and are associated with birth trauma, forceps, and vacuum-assisted deliveries. They present as scalp swelling and are usually identified shortly after birth. During sonographic examination, if an ultrasound beam scatters off a mirror-like interface, it creates mirror-image artifacts that can cause a diagnostic dilemma. In this case report, a six-day-old neonate presented with a right-side parietal cephalhaematoma that appeared to resemble an epidural haematoma on routine sonographic examination. Gray scale ultrasound revealed an anechoic structure resembling an epidural haematoma in the right parietal region. However, a non-contrast-enhanced computed tomography (NECT) scan of the brain showed a cephalhaematoma without an underlying epidural haematoma. Further evaluation using colour Doppler sonography revealed normal vascular findings within an anechoic space, and gray scale imaging in the sagittal plane showed normal cerebral parenchyma without midline shift. These findings helped identify the observed structure as a mirror-image artifact. It is important to note that these artifacts can lead to diagnostic errors, resulting in additional investigations and causing anxiety for parents. Understanding and being aware of these artifacts can help avoid unnecessary imaging and reduce radiation exposure.