Simultaneously Acquired MRI Arterial Spin-Labeling and Interictal FDG-PET Improves Diagnosis of Pediatric Temporal
A M Khalaf1, H R Nadel2, H M Dahmoush2
1From the Stanford University School of Medicine, Department of Radiology, Division of Nuclear Medicine & Molecular Imaging, Division of Pediatric Radiology, Division of Neuroimaging & Neurointervention, Stanford University, Stanford, California khalafam@stanford.edu.
Background And Purpose:
Interictal FDG-PET scans are a routine diagnostic technique for the identification of epileptogenic foci in the presurgical work-up of medically refractory pediatric epilepsy. With the advent of PET/MR imaging, it has become possible to simultaneously acquire FDG-PET and arterial spin-labeling perfusion data. The objective of this study was to evaluate whether the incorporation of arterial spin-labeling data with interictal FDG-PET could improve the diagnostic performance metrics of FDG-PET for identification of epileptogenic foci.
Materials And Methods:
Forty-five pediatric patients with a mean age of 10.8 years were retrospectively included in this study. These patients all underwent PET/MR imaging to diagnose suspected focal epilepsy.
Results:
When compared to interpretations of interictal FDG findings alone, FDG combined with arterial spin-labeling findings resulted in significantly decreased sensitivity (0.64 versus 0.52, P = .02), significantly increased specificity (0.50 versus 0.75, P = .04), and an increased positive predictive value (0.59 versus 0.75). The decreased sensitivity was found to be primarily driven by patients with extratemporal lobe epilepsy, as a subgroup analysis showed decreased sensitivity for patients with extratemporal epilepsy (0.52 versus 0.38, P = .04), but not for temporal epilepsy (0.83 versus 0.75, P = .16). Additionally, substantial agreement between focal FDG hypometabolism and arterial spin-labeling hypoperfusion was demonstrated with the Cohen κ (0.70, P < .01).
Conclusions:
These findings suggest that simultaneously acquired interictal FDG-PET and arterial spin-labeling data can improve the diagnosis of epileptogenic foci, especially in the setting of temporal lobe epilepsy where they improve specificity and positive predictive value, with preservation of sensitivity.
Insights
Combining FDG-PET and arterial spin-labeling (ASL) in pediatric epilepsy improves diagnostic specificity for epileptogenic foci. This PET/MR imaging approach enhances accuracy, particularly for temporal lobe epilepsy cases.
Area of Science:
- Neuroimaging
- Epilepsy diagnostics
- Nuclear medicine
Background:
- Interictal FDG-PET is standard for identifying epileptogenic foci in pediatric epilepsy surgery work-up.
- Advancements in PET/MR imaging allow simultaneous acquisition of FDG-PET and arterial spin-labeling (ASL) perfusion data.
- Evaluating combined imaging modalities is crucial for improving diagnostic accuracy.
Purpose of the Study:
- To assess if incorporating ASL data with interictal FDG-PET enhances diagnostic performance for epileptogenic foci.
- To determine the impact on sensitivity, specificity, and predictive values in pediatric focal epilepsy.
Main Methods:
- Retrospective analysis of 45 pediatric patients with suspected focal epilepsy undergoing PET/MR imaging.
- Comparison of diagnostic metrics between FDG-PET alone and combined FDG-PET with ASL findings.
- Subgroup analysis for temporal versus extratemporal lobe epilepsy.
Main Results:
- Combined FDG-PET and ASL showed significantly decreased sensitivity (0.52 vs. 0.64) but significantly increased specificity (0.75 vs. 0.50) compared to FDG-PET alone.
- Positive predictive value increased from 0.59 to 0.75 with the combined approach.
- Decreased sensitivity was notable in extratemporal lobe epilepsy patients, while temporal lobe epilepsy showed preserved sensitivity with improved specificity and PPV.
Conclusions:
- Simultaneous FDG-PET and ASL data improve the diagnosis of epileptogenic foci in pediatric epilepsy.
- The combined approach particularly benefits temporal lobe epilepsy by enhancing specificity and positive predictive value while maintaining sensitivity.
- This integrated PET/MR imaging strategy offers a more refined diagnostic tool for presurgical epilepsy evaluation.
