# Head to head comparison between arterial spin labelling MRI and [18F]FDG-PET in presurgical evaluation of epilepsy in children: the role of voxel-based asymmetry index analysis

## TL;DR

This study compares two imaging techniques for identifying brain areas causing seizures in children before surgery, finding that one becomes more accurate with a specific analysis method.

## Contribution

The study introduces voxel-based asymmetry index analysis to improve the accuracy of arterial spin labelling MRI in pediatric epilepsy evaluation.

## Key findings

- Arterial Spin Labelling MRI with asymmetry index analysis achieves results comparable to [18F]FDG-PET in identifying the epileptogenic zone.
- Visual analysis of Arterial Spin Labelling MRI alone has a significantly lower concordance rate with the epileptogenic zone.
- Voxel-based asymmetry index analysis significantly increases the accuracy of Arterial Spin Labelling MRI in pediatric patients.

## Abstract

Arterial Spin Labelling MRI is a neuroimaging technique able to evaluate brain perfusion, an indirect measure of brain metabolism and function. Arterial Spin Labelling MRI showed to have performances comparable to [18F]fluorodeoxyglucose-PET in in epilepsy, yet literature data is still lacking about its use in children and the value of voxel-based asymmetry index analysis. Purpose of the project is to compare the Arterial Spin Labelling MRI and [18F]fluorodeoxyglucose-PET ability to identify the epileptogenic zone before and after asymmetry index analysis in children.

In this observational study, paediatric patients with focal onset drug-resistant epilepsy that underwent presurgical evaluation, including Arterial Spin Labelling MRI and [18F]fluorodeoxyglucose-PET, were enrolled. The epileptogenic zone was defined by anatomo-electroclinical correlation and post-surgical outcome, when feasible. The rates of concordance with the epileptogenic zone of Arterial Spin Labelling MRI and [18F]fluorodeoxyglucose-PET before (visual analysis) and after asymmetry index analysis, were calculated. Statistically significant differences between were determined using Mc Nemar’s test (p < 0.05).

28 paediatric patients (mean age 10.07 years, 15 females) with focal epilepsy were enrolled; 22 underwent epilepsy surgery (mean age 9.86 years, 12 females). When comparing the techniques, visual analysis of Arterial Spin Labelling MRI had a significantly lower rate of concordance with the epileptogenic zone (p < 0.05).

Voxel-based asymmetry index analysis increased significantly the rate of concordance of Arterial Spin Labelling MRI with the epileptogenic zone, achieving results comparable with [18F]fluorodeoxyglucose-PET in a cohort of paediatric patients.

The online version contains supplementary material available at 10.1007/s10072-026-08891-y.