The parasagittal dura (PSD), a mesenchymal stromal tissue which lies within the two layers of the dura mater (1), is considered to be a site of brain immune-surveillance and one of the pathways for drainage of cerebrospinal fluid (2–5). PSD is readily visible on magnetic resonance (MR) imaging (6) and its volume changes have been associated with brain neurodegenerative processes (7). Different semi-automatic and automatic methods have been developed and validated for segmenting the PSD in adult cohorts (8–10). However, none of these methods are available for segmenting this structure in the developing brain. Here an automatic tool to segment PSD using 3D-T2 Fluid Attenuated Inversion Recovery (3D T2-FLAIR) MR images in children with autism spectrum disorder (ASD) is proposed. The choice of using 3D T2-FLAIR was motivated by its great contrast between PSD and adjacent subarachnoid space, facilitating both PSD identification and manual segmentation. Also, 3D T2-FLAIR is routinely acquired in clinical protocols, making the tool valuable for translational studies. Furthermore, initial studies on the role of PSD in neuroinflammation and CSF drainage used 3D T2-FLAIR (1, 6, 10, 11). The cohort comprised 65 children clinically diagnosed with ASD, aged 2 to 10 years. Manual segmentations, performed by a neuroradiologist, were considered as ground truth. The algorithm achieved a Dice Score Coefficient of 0.85, a volumetric similarity of 0.97 and a Hausdorff distance of 22.1. This tool represents the first publicly available automatic PSD segmentation method for paediatric MR images based on clinically adopted 3D T2-FLAIR image, providing support for the quantification of PSD in children with ASD.

References

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