Analysis of CT and MRI Manifestations of Joubert Syndrome

Abstract

Objective: To investigate the computed tomography and magnetic resonance imaging manifestations of Joubert syndrome (JS).

Method: In this retrospective analysis, we investigated the clinical and imaging characteristics of JS in a cohort of twelve pediatric patients with confirmed diagnoses. Specifically, we analyzed both computed tomography (CT) and magnetic resonance imaging (MRI) manifestations in this population. CTs were performed on four patients and MRIs were performed on twelve, respectively.

Results: JS is characterized by specific CT and MRI findings, including midline fissure, batwing, or triangular formations of the fourth ventricle between the bilateral cerebellar hemispheres, and molar sign at the midbrain level. All twelve cases in this cohort exhibited these traits, along with other cerebral abnormalities, such as dysplasia of the corpus callosum in two cases, gray matter heterotopia in one case, and occipital meningocele in one case.

Conclusion: JS has distinctive CT and MRI characteristics that can be clinically identified.

Keywords: CT; Joubert syndrome; MRI; dysplasia of the cerebellar vermis.

Figure 1

A three-year-old boy with a speech disorder and lifelong difficulty understanding simple instructions. A) A hypoplastic cerebellar vermis is evident on the axial CT image, with a midline fissure sign between the bilateral cerebellar hemispheres (short arrow), and a batwing sign on the fourth ventricle (long arrow). B) The upper cerebellar peduncles are thickened and elongated, forming a molar sign (arrow) with the midbrain.

Figure 2

An eight-year-old girl with a three-year developmental delay. Fine motor skills of the hands were deficient, and separation movements were insufficient. A) The T1WI transverse view revealed a molar sign (arrow). B) The T2WI transverse view showed bilateral interhemispheric midline fissure sign (short arrow) and fourth ventricle batwing sign (long arrow).

Figure 3

A male infant, aged two months, presented with hoarseness for one day and head shaking for half a day. The sagittal T2WI revealed slight thinning of the midbrain, slight enlargement of the interpeduncular fossa, and thickening and elongation of the upper cerebellar peduncle, which was running horizontally (indicated by arrow).

Figure 4

A three-year-old male toddler with difficulty walking unassisted, poor verbal skills, and developmental delays. A sagittal T2WI scan revealed the absence of the body and splenium of the corpus callosum, and the gray matter heterotopia (arrows).

Figure 5

A seven-month-old girl with a pulsating occipital mass lasting seven months. A) The midline fissure (arrow) between the bilateral cerebellar hemispheres, the great occipital fossa (long arrow), and a localized occipital bone defect with accompanying meningeal and brain herniation (short arrow). B) Enlargement of the posterior fossa cistern (long arrow) and localized bony defect with accompanying meningeal herniation (short arrow) are visible in the sagittal T1-weighted image.