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Updated: Sep 28, 2025
Modeling Brain Metastases Through Intracranial Injection and Magnetic Resonance Imaging
Published on: June 7, 2020
MRI sequences and interslice gap influence leptomeningeal metastasis detection in children with brain tumors
Julie H Harreld1,2,3, Ayaz Khan4, Jacqueline Angel1
1Department of Diagnostic Imaging, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Mail Stop 220, Memphis, TN, 38015, USA.
Purpose:
Accurate detection of leptomeningeal metastasis (LM) is critical for risk stratification and treatment of pediatric brain tumors. Poor-quality staging MRI has been associated with decreased survival in this population, but technical factors differentiating good from poor quality screening MRIs remain undefined. To test the hypothesis that key technical factors are associated with accurate MRI diagnosis of leptomeningeal metastasis in children with leptomeningeal seeding brain tumors.
Methods:
MRIs acquired at outside facilities and repeated in our institution within 35 days for 75 children with leptomeningeal seeding tumors were assessed for slice thickness and gap; use of T2 FLAIR + Contrast, acquisition plane of 3DT1WI + Contrast (brain); axial T1 + Contrast sequence, and use of pre-contrast T1 images (spine). Reported findings were recorded as positive, negative, or equivocal for LM and classified as true positive (TP; unequivocal metastasis), false negative (FN; not reported), false positive (FP; resolved without treatment), or true negative. Wilcoxon signed-rank and Fisher's exact test were used to assess technical differences between TP and FN MRIs.
Results:
Rate of LM detection was greater with smaller interslice gap in brain (P = 0.003) and spine (P = 0.002); use of T2 FLAIR + Contrast (P = 0.005) and sagittal plane for 3DT1WI + Contrast (P = 0.028) in brain; and use of alternatives to axial TSE/FSE in spine (P = 0.048). Slice thickness was not significant. Pre-contrast T1WI did not contribute to LM diagnosis in spine.
Conclusion:
Using post-contrast T2 FLAIR and sagittal 3DT1 in brain, small/no interslice gap, and avoiding TSE/FSE axials in spine may facilitate leptomeningeal metastasis detection in children with brain tumors.
Insights
Accurate MRI detection of leptomeningeal metastasis (LM) in children with brain tumors is improved by using specific technical factors. Smaller gaps between slices and T2 FLAIR with contrast enhance brain LM detection.
Area of Science:
- Pediatric Neuro-oncology
- Medical Imaging
- Radiology
Background:
- Accurate detection of leptomeningeal metastasis (LM) is crucial for managing pediatric brain tumors.
- Poor-quality staging MRIs are linked to reduced survival in children with brain tumors.
- Technical factors influencing MRI quality for LM detection are not well-defined.
Purpose of the Study:
- To identify key technical factors associated with accurate MRI diagnosis of LM in pediatric brain tumor patients.
- To determine if specific MRI acquisition parameters improve LM detection rates.
Main Methods:
- Retrospective analysis of 75 pediatric patients with leptomeningeal seeding brain tumors.
- Comparison of MRIs from outside facilities and institutional re-scans within 35 days.
- Assessment of technical factors including slice thickness, gap, contrast use, and acquisition planes for brain and spine.
Main Results:
- Smaller interslice gaps in brain and spine MRIs significantly increased LM detection rates.
- Use of T2 FLAIR with contrast and sagittal plane for 3DT1WI in brain improved detection.
- Employing alternatives to axial TSE/FSE for spine imaging also enhanced LM detection.
Conclusions:
- Optimizing MRI technical factors can improve leptomeningeal metastasis detection in pediatric brain tumors.
- Specific sequences (T2 FLAIR, sagittal 3DT1) and minimal interslice gaps are recommended for brain imaging.
- Avoiding axial TSE/FSE sequences for spine imaging may aid LM diagnosis in this population.
