Ultrasound posterior fossa images in preterm infant

Ultrasound images of the posterior fossa in a preterm neonate (gestational age 29 weeks), using a high frequency linear transducer.
Images A, B, C - Ultrasound scan through mastoid fontanel in the axial/transverse plane with superior axial view (A), midaxial view (B), and inferior axial view (C). In (A), long arrow points to pons, and in (B), the short arrow indicates the fourth ventricle and the asterisk indicates the cerebellar peduncles.
Images D, E - Ultrasound scan through mastoid fontanel in the coronal plane with anterior coronal view (D) and posterior coronal view (E). Arrowhead points to the fourth ventricle in (D).