case_images: PMC11760794_01
case_images: Midline sagittal T1-weighted imaging (A) demonstrates significant ventral flattening of the pons, with dorsal rounded fullness protruding into the fourth ventricle. Axial T2-weighted imaging at the level of the isthmus (B) reveals the classic "molar tooth" configuration, characterized by laterally displaced superior cerebellar peduncles and a deep interpeduncular fossa. Additional axial T2-weighted imaging (C) shows hypoplasia of the middle cerebellar peduncles. Axial T1-weighted imaging without contrast (D) depicts a smaller right cranial nerve VII/VIII complex; however, no high-resolution T2 images were available for further evaluation. Another axial T2-weighted image (E) highlights a smaller right internal auditory canal compared to the left. Finally, axial susceptibility-weighted (F) and phase (G) imaging demonstrate several foci of susceptibility artifact in both cerebellar hemispheres, consistent with prior microhemorrhages, without evidence of mass effect or edema.
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case_images: PMC11760794_01_gr1.jpg
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case_images: Further investigations included Magnetic Resonance Imaging (MRI), which revealed abnormal contours of the pons, abnormal superior and middle cerebellar peduncles, a hypoplastic right cranial nerve VII/VIII complex, and a small right internal auditory canal, all highly suggestive of pontine tegmental cap dysplasia (Fig. 1).