Brain herniation into the transverse sinuses’ arachnoid granulations in the pediatric population investigated with 3 T MRI

We aimed to evaluate the frequency, radiological–clinical findings of brain herniation into arachnoid granulation (BHAG) in pediatric age group using 3 T magnetic resonance imaging. Patients were under 18 years of age and underwent brain MRI examination which consists of 3D T1, 3D T2 FLAIR and 3D T2 sequences. A total of 2320 patients were enrolled in the study. All cases of AG into transverse sinus were included. The location of the AG, the deep, transverse, vertical and neck diameters and volume of AG were recorded. Clinical findings and imaging findings of patients were also recorded. The patients were categorized as BHAG and AG without brain herniation (AGWBH). The mean diameters (deep, transverse, vertical and neck) of AG, volume of AG, age, sex, clinical findings and imaging findings were evaluated and compared in each group. 135 patients (71 female, 64 male) had AG in a total of 2320 patients (prevalence 5.81%). Fifteen patients (10.7% of all patients, 11 female, 4 male) had BHAG. The mean diameters (deep, transverse, vertical and neck) and volume of AGWBH were 5.23 ± 1.91, 4.07 ± 1.58, 4.99 ± 1.68, 3.64 ± 1.84 mm and 85.05 ± 89.10 mm³, respectively. The mean diameters (deep, transverse, vertical and neck) and volume of BHAG were 7.46 ± 2.6, 6.85 ± 2.34, 8.32 ± 2.35, 5.41 ± 1.79 mm and 331 ± 361.26 mm³, respectively. The mean diameters and volume of BHAG were significantly larger than AGWBH (p < 0.001 for all parameters). There was no significant difference related to clinical and imaging findings between groups (p > 0.05). Brain herniation into arachnoid granulation is seen in pediatric age group as frequently as adults. Its frequency is not related to age. It is not significantly associated with neurological symptoms. As the AG size increases, the risk of BHAG increases.