Learning objectives
To review the normal radiological anatomy of the brainstem and cerebellum.
To illustrate the MR imaging features of infratentorial lesions in the adulthood.
To describe an imaging strategy to accurately diagnose each case,
based on MRI appearance and clinical information.
Background
The infratentorial region is a cavity delimited superiorly by the tentorium cerebelli,
inferiorly by the foramen magnum,
anteriorly by the apex of petrous temporal,
posteriorly by occipital bone and laterally by the squamous and mastoid portions of temporal bones.
It contents the cerebellum,
midbrain,
medulla and pons.
The best imaging modality to study the infratentorial region is the MR.
The basic radiological structure of cerebellum includes hemispheres,
vermis and pedicles.
Cerebellar hemispheres and vermis is are divided into lobules,
which are fully demarked on MR....
Findings and procedure details
INFLAMMATORY DISEASES
MULTIPLE SCLEROSIS
- Definition: Multiple sclerosis (MS) is a progressive neurodegenerative disorder characterized histopathologically by multiple inflammatory demyelinating foci called “plaques.”
- Location: Most MS plaques are supratentorial.
Less than 10% occur in the posterior fossa although infratentorial lesions are relatively more common in children.
MS plaques in the deep cerebral white matter are linear,
round,
or ovoid lesions that are oriented perpendicular to the lateral ventricles at or near the callososeptal interface.
Centripetal perivenular extension is common,
causing the appearance of “Dawson...
Conclusion
Based on the location of the lesions in the infratentorial region,
and their performance in the different MRI sequences,
we were able to develop an scheme based in both MRI and clinicaldata aimed to narrow the differentials and to make a specific diagnosis of the different lesions under evaluation,
using as a starting point whether the lesion is focal (Figure 24),
diffuse (Figure 25) and/or has meningeal disease associated (Figure 26).
Personal information
Diego Enrique Nova Vaca.
Department of Radiology and Diagnostic Imaging.
Hospital Universitari de Bellvitge,
L'Hospitalet de Llobregat,
Spain.
Angels Camins Simon.
Department of Neuroradiology.
Hospital Duran i Reynals -Institut Català d'Oncologia,
Hospital Universitari de Bellvitge.L'Hospitalet de Llobregat,
Spain.
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