Cerebrospinal fluid seeding from pediatric intra and extra-cranial tumors: optimization of the MRI protocol

Abstract Background Cerebrospinal fluid (CSF) seeding is a mechanism by which central nervous system (CNS) tumors spread, involving the dissemination of malignant cells along CSF pathways. Early detection is critical, as improved diagnostic accuracy may positively impact patient outcomes. This study aimed to compare contrast-enhanced T1-weighted spine magnetic resonance imaging (MRI) sequences with and without fat saturation for detecting and visualizing CSF seeding lesions. Methods This retrospective study included 49 pediatric cancer patients of both sexes, diagnosed with either primary CNS tumors (brain or spine) or secondary CNS involvement from extra-cranial solid tumors. All patients had positive CSF cytology for seeding and available spinal MRI studies for evaluation. Results The overall image quality and anatomical detail depiction scores were significantly higher for the contrast-enhanced T1-weighted sequence without fat saturation compared to the fat-saturated sequence ( P < 0.001). Conversely, artifact severity and CSF seeding lesion visibility scores were significantly higher in the fat-saturated sequence ( P < 0.001). Conclusion The contrast-enhanced T1-weighted sequence without fat saturation offers superior diagnostic quality and remains an essential sequence for accurate detection of CSF seeding lesions in the spine.