Anatomic Illustrations of Cranial Ultrasound Images Obtained Through the Mastoid Fontanelle in Neonates

ABSTRACT

PURPOSE: Neonatal cranial sonongraphy performed through the mastoid fontanelle is more useful to evaluate the peripheral structures at the convexity of the cerebral hemispheres and brainstem rather than that performed through the anterior fontanelle. The purpose of this study is to demonstrate the anatomy of the extracerebral CSF space and brainstem and to suggest appropriate scan planes for performing neonatal cranial sonography through the mastoid fontanelle using MRI and multiplanar reconstruction programs. MATERIALS AND METHODS: A neonate with normal features on ultrasonography and good image quality on MRI, including the 3D-SPGR axial scans, was selected. We made the reconstructed MR images corresponding to the sonongraphic planes and the anatomic models of the neonatal cranial sonographic images by using axial MRI as the standard reference on the same screen. We demonstrated the sonographic images at the levels of the body of the caudate nucleus and lentiform nucleus, the head of the caudate nucleus and thalamus, the third ventricle and midbrain, and the midbrain and cerebellar vermis on the oblique axial scans. Four oblique coronal images at the levels of the periventricular white matter, basal ganglia, thalamus and tentorium were also obtained. RESULTS: We illustrated the anatomic atlas with including four oblique axial scans and four oblique coronal scans that corresponded to the neonatal cranial sonographic images through the mastoid fontanelle. CONCLUSION: We objectively analyzed the anatomy of the extracerebral CSF space and brainstem by using MRI and multiplanar reconstruction programs and we provided the standardized sonographic scan planes through the mastoid fontanelle. This study will be very helpful for evaluating the abnormalities of the peripheral structures at the convexity of the cerebral hemispheres and brainstem.