Refractory seizures: Prediction of outcome of surgical intervention based on results from PET-CT, PET-MRI and electroencephaolography.

PURPOSE: The purpose of this article is to evaluate the effectiveness of fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) and PET-magnetic resonance imaging (MRI) with scalp and intracranial electroencephalogram (EEG) in predicting surgical outcomes in patients with refractory seizures. METHODS: Patients who underwent PET-CT and MRI fusion, scalp and intracranial EEG, and subsequent surgical intervention were retrospectively included. PET-CT were fused with MRI and interpreted by an experienced blinded reader. An area of hypometabolism on PET was identified as the location of the epileptic focus. The site of seizure focus was correlated with scalp and intracranial EEG findings. Surgical outcomes were evaluated. Thirty-six patients were included; all had presurgical PET-CT, scalp EEG, and PET-MRI fusion, and 28 of these patients had intracranial EEGs. RESULTS: PET-CT showed concordance of epileptic foci with scalp EEG in 7/36 patients (19%) and with intracranial EEG in 9/28 patients (32%). PET-MRI was concordant with scalp EEG in 6/36 patients (17%) and with intracranial EEG in 8/28 patients (29%). All patients with concordance of epileptic foci between PET-CT and PET-MRI and scalp EEG had improvement or resolution of seizures postintervention, and 89% of patients had concordance between intracranial EEG and PET studies. However, 45% of patients with discordant PET-CT and scalp EEG, 37% with discordance PET-CT and intracranial EEG, 43% with discordant PET-MRI and scalp EEG, and 35% of patients with discordant PET-MRI and intracranial EEG did not improve postsurgically. CONCLUSION: Concordance of epileptic foci localization between PET imaging and EEG yields favorable postoperative outcome in nearly all patients, whereas discordance has an equal probability of favorable vs unfavorable outcomes.

Improving Hepatobiliary Imaging as a Physiologic Test with Superior Clinical Outcomes.

This study aims at prospectively evaluating the difference in the effect of cholecystokinin (CCK) and half-and-half milk (HHM) administered in the same patient on gallbladder contractility and correlation with clinical outcomes. Upon gallbladder visualization during standard hepatobiliary imaging, 0.02 µg/kg of CCK was injected over 3 min, and additional 30 min of dynamic imaging was obtained. Patients with gallbladder ejection fraction (GBEF) <35% after CCK were administered 8 oz of HHM followed by 30 min of imaging. The GBEF was recalculated. The number of patients whom GBEF changed from below 35% (abnormal) after CCK to above 35% (normal) after HHM was recorded. Follow-up of the clinical outcome at 6 months was performed. Fifty patients with abnormal GBEF were prospectively included. The average GBEF after CCK was 14.7% ± 8.5% and after HHM was 30.7% ± 20.8%. The average increase in GBEF with HHM was 16.0% ± 22.2%. The GBEF changed from abnormal to normal in 17 patients (34%). The remaining 33 patients remained abnormal. Clinical outcomes at 6 months were available in 47 patients. Cholecystectomy was performed in 60% of patients with abnormal GBEF with CCK and HHM with resolution or improvement of pain. Two of 16 patients (12%) with abnormal GBEF after CCK but normal after HHM had cholecystectomies with pain improvement, while 8 out of these patients (50%) were diagnosed and treated with other disorders and improved. Hepatobiliary imaging with HHM stimulation is a superior physiologic test which can lower the number of unnecessary cholecystectomies and misdiagnoses as functional cholecystitis.