[¹⁸F] Fluorodeoxyglucose–Positron-Emission Tomography and MR Imaging Coregistration for Presurgical Evaluation of Medically Refractory Epilepsy

Abstract

SUMMARY:Epilepsy is a chronic disorder affecting approximately 1% of the population of the world. Approximately one third of patients with epilepsy remain refractory to medical therapy. For these patients, surgery is a curative option. In order for surgery to be considered, precise localization of the structural abnormality is needed. When MR imaging findings are normal, more sensitive techniques such as positron-emission tomography (PET) can help find the abnormality. Combining MR imaging and PET information increases the sensitivity of the presurgical evaluation. In this review, we discuss the clinical applications of coregistration of [18 F] fluorodeoxyglucose (FDG)-PET with MR imaging for medically refractory epilepsy. Because FDG-PET/MR imaging coregistration has been a routine component of the presurgical evaluation for patients with epilepsy at our institution since 2004, we also included cases from our data base that exemplify the utility of this technology to obtain better postsurgical outcomes.

Recent Developments in Combined PET/MRI

“…In these cases, further evaluation with nuclear medicine techniques including [ 18 F]-FDG PET and ictal/interictal perfusion SPECT is indicated [30]. In these cases, coregistration of the PET/SPECT and MRI data leads to improved detection of epileptogenic foci [31]. Importantly, patients without MRI lesions, and with positive PET scans, have similar outcomes to those with MRI findings following epilepsy surgery [32,33].…”

Current status and future role of brain PET/MRI in clinical and research settings

“…Studies combining MRI and [ 18 F]FDG PET in the presurgical assessment of refractory epilepsy (i.e. medial temporal sclerosis, focal cortical dysplasia and tuberous sclerosis complex) are numerous and have recently been reviewed by Lee and Salamon [91]. Briefly, they found that coregistration of [ 18 [94].…”

“…Aberrant brain function then needs to be assessed using other noninvasive imaging modalities such as magnetoencephalography, SPECT and PET. Interictal [ 18 F]FDG PET, that shows hypometabolism in epileptogenic foci, was the first imaging modality used in the planning of surgery for TLE [90] and is now routinely used in specialized PET centres [91]. Studies combining MRI and [ 18 F]FDG PET in the presurgical assessment of refractory epilepsy (i.e.…”

Balancing Clinical and Pathologic Relevance in the Machine Learning Diagnosis of Epilepsy

“…Using our knowledge of normal physiology, this comparison has been used to describe how the complexity of EEG recording during seizure (ictus) is less than that of interictal EEG [1, 2]; how epileptic lesions are associated with focal cortical atrophy and hyperintensity on MRI [12]; and how focal interictal hypometabolism in FDG-PET can indicate the seizure onset zone [13]. These differences are thought to be macro-scale features that confirm our understanding of epilepsy on a neural level.…”