A systematic review on volumetric analysis in orbital MRI.

Aim: Volumetric analysis of orbital soft tissues using magnetic resonance imaging (MRI) offers valuable diagnostic and pathophysiological insights into orbital inflammation, trauma, and tumors. However, the optimal MRI protocols and post-processing methods for specific conditions remain unclear.

Methods: A systematic search was performed in PubMed/MEDLINE, Web of Science, and Cochrane Library for all studies published before November 2024. This review adhered to PRISMA guidelines and was prospectively registered. Primary outcomes included (i) MRI acquisition parameters, (ii) post-processing volumetry techniques, and (iii) regions of interest (ROI). Secondary outcomes assessed clinical relevance and validation methods.

Results: From 4323 records, 35 articles were included. Significant heterogeneity was observed regarding MRI acquisition and post-processing techniques. Volumetry most commonly targeted extraocular muscles and orbital fat, although definitions of ROI borders varied widely. Analysis of the globe, orbital cavity, optic nerve, and lacrimal gland was less frequent. Validation of volumetric methods was reported in only a minority of studies.

Conclusions: Accurate interpretation of volumetric data requires careful consideration of technical variables. Standardization of acquisition protocols, validated segmentation methods, and automated volumetry approaches are essential for enhancing reproducibility and clinical applicability. This systematic review provides a comprehensive framework for future research in orbital MRI volumetry.