Use of black-bone MRI in the diagnosis of the patients with posterior plagiocephaly.

PURPOSE: Ionising radiation exposure is especially harmful to brain development. The purpose of this study was to evaluate whether black-bone (BB) magnetic resonance imaging (MRI), a non-ionising imaging method, offers an alternative to ionising imaging methods such as computed tomography (CT) in the examination of cranial deformities.

METHODS: From 2012 to 2014, a total of 408 children were referred to the Craniofacial Centre at the Helsinki University Hospital for further examination due to flatness of the posterior skull. Fifteen of these patients required further diagnostic imaging. To avoid ionising radiation, we used an MRI protocol that included sequences for evaluation of both brain anatomy and skull bone and sutures by BB-MRI. A semi-automatic skull segmentation algorithm was developed to facilitate the visualisation. Two patients with scaphocephaly were included in the study to confirm the ability to differentiate synostosis with BB-MRI.

RESULTS: We obtained informative 3D images using BB-MRI. Seven patients (7/15, 46.7%) had plagiocephaly on the right side and seven on the left side (7/15, 46.7%). One patient (1/15, 6.7%) had symmetric posterior flatness affecting both sides. Neither structural nor signal-intensity alterations of the brain were detected in visual analysis.

CONCLUSION: BB-MRI provides an alternative to CT when imaging craniofacial deformities. BB-MRI provides not only high-quality 3D-reconstructed imaging of the bony structures and sutures but also information on brain structure in one imaging session. With further development, this method could replace ionising radiation-based methods in analysing deformities of the skull.