Contrast-enhanced 3-dimensional Fluid-attenuated Inversion Recovery Sequences Have Greater Sensitivity for Detection of Leptomeningeal Metastases in Pediatric Brain Tumors Compared With Conventional Spoiled Gradient Echo Sequences

Abstract

Postcontrast 3-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences have reduced vascular and flow-related artifacts and high sensitivity to low gadolinium concentrations. We compared the performance of postcontrast spoiled gradient echo images to 3D-FLAIR in the detection of leptomeningeal metastases in 47 pediatric patients with brain tumors. We found 10 cases with more leptomeningeal signal abnormalities on 3D-FLAIR. Overall there were significantly more lesions on 3D-FLAIR than spoiled gradient echo sequences. We believe the increased detection of leptomeningeal signal abnormality is due to increased sensitivity for low concentrations of gadolinium in regions of early blood brain barrier breakdown. Our study was limited by the lack of leptomeningeal metastases in cerebrospinal fluid sampling. We plan to conduct future studies which will determine whether the time-based concentration of gadolinium affects the performance and results. Future studies will also require more cases of pathology-proven leptomeningeal disease.

Imaging of pediatric brain tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper

“…Depending on the technique and slice thickness used, post-contrast T2-FLAIR can outperform post-contrast T1-weighted images for detecting leptomeningeal metastatic disease, although there have been conflicting reports comparing the two techniques. 25,26 However, in conjunction with post-contrast T1-weighted images, post-contrast T2-FLAIR imaging considerably improves the sensitivity and confidence of leptomeningeal metastatic disease detection. [27][28][29] Therefore, it is recommended that a T2-FLAIR sequence be performed after administration of contrast.…”

“…T2‐FLAIR imaging also overcomes the drawbacks of sulcal vascular enhancement and phase‐shift artifacts seen in T1‐weighted sequences. Depending on the technique and slice thickness used, post‐contrast T2‐FLAIR can outperform post‐contrast T1‐weighted images for detecting leptomeningeal metastatic disease, although there have been conflicting reports comparing the two techniques 25,26 . However, in conjunction with post‐contrast T1‐weighted images, post‐contrast T2‐FLAIR imaging considerably improves the sensitivity and confidence of leptomeningeal metastatic disease detection 27–29 .…”

“…3D T2-FLAIR images acquired using the variable flip angle TSE technique may further improve leptomeningeal metastasis detection by providing thinner slices and fewer flow artifacts in cisterns and ventricles compared with 2D T2-FLAIR images26 (Grade: B; SOR: 1.3, very strong recommendation).…”

European Society for Paediatric Oncology (SIOPE) MRI guidelines for imaging patients with central nervous system tumours

“…3D FLAIR can be used instead of 2D FLAIR but not if 2D sequences have been used for the same individual on previous occasions. The practice of acquiring FLAIR postcontrast has been popular and post-contrast 3D T2 FLAIR has been shown to be highly sensitive in identifying leptomeningeal metastasis in single centre studies [22,23]. Routine use of contrast-enhanced FLAIR will need further validation in the paediatric brain tumour population, and even if used should be in addition to pre-contrast FLAIR rather than as a replacement.…”

Positron emission tomography and magnetic resonance imaging in primary central nervous system lymphoma—a narrative review

“…The European Association of Neuro-Oncology (EANO) guidelines recommend brain MRI using T2-weighted/fluid-attenuated inversion recovery (T2/FLAIR) and T1-weighted sequences pre-contrast and post-contrast injection for diagnosis and follow-up ( 33 ). Studies have suggested that post-contrast T2/FLAIR images are more sensitive for detecting disease, with the combination of T1- and T2-weighting to suppress the signal from bulk fluid helping to increase lesion conspicuity particularly for leptomeningeal disease near the cortex or subependymal disease along the ventricles ( 34 , 35 ). The recommendations specify T2/FLAIR acquisition after contrast injection and prior to post-contrast T1-weighted images.…”