Subsequent experience in hybrid PET-MRI for evaluation of refractory focal onset epilepsy

摘要

PurposeEpilepsy surgery is the most successful method of treating medically unresponsive epilepsy, but carries a risk of morbidity. PET/MR is an emerging technique that increases detection of focal lesions whose resection may result in symptom remission. MethodsRetrospective review of 74 focal epilepsy patients over a period of 3 years who had a PET/MR was performed following IRB permission and informed consent. 27 patients underwent surgery or RNS (responsive neurostimulator) placement. ResultsHybrid PET-MR identified new anatomic or functional lesions in 10 patients not identified with standalone 3?T MR. Of the 27 patients who underwent focal surgery (19) or RNS placement (8), 24 showed improvement (Engel’s I-III), 2 did not (Engel’s IV), and one had an RNS explanted due to infection. MR and PET were read by 2 separate neuroradiologists and nuclear medicine physicians, respectively. Modalities were evaluated in terms of ability to detect the correct lobe and side for a focal lesion whose resection improved symptoms. Prior standalone MR exhibited 71–77% sensitivity and 0% specificity (as there were only 2 nonresponders), MR associated with PET/MR had 68–71% sensitivity and 0–50% specificity (depending on whether a lesion was seen on one of the nonresponders), and PET had 68–71% sensitivity and 25–33% specificity. Using either PET or MR to identify a focal lesion, PET/MR had sensitivity of 78–82% and specificity 0–50%. ConclusionsPET-MR provides additional sensitivity when used as two combined modalities for detecting possible epileptic foci.