Abstracts

Quantitative-PET-guided MRI Post-processing in MRI-negative Epilepsies

Abstract number : 2.220
Submission category : 5. Neuro Imaging / 5A. Structural Imaging
Year : 2017
Submission ID : 349059
Source : www.aesnet.org
Presentation date : 12/3/2017 3:07:12 PM
Published date : Nov 20, 2017, 11:02 AM

Authors :
Yicong Lin, Xuanwu Hospital, Capital Medical University, Beijing, China; Yu-Hua Dean. Fang, 3. Department of Biomedical Engineering, National Cheng Kung University, Tainan, Taiwan; Guiyun Wu, Cleveland Clinic; Stephen Jones, Cleveland Clinic; Richard Pray

Rationale: In the presurgical evaluation of “magnetic resonance imaging (MRI)-negative” pharmacoresistant focal epilepsy patients, discovering and identifying subtle abnormalities is of paramount importance. A voxel-based MRI post-processing technique, implemented in a morphometric analysis program (MAP) helps to provide suspicious subtle abnormality candidates. Our study utilizes quantitative PET (QPET) analysis to complement MRI post-processing, to facilitate objective identification of subtle abnormality. Methods: We retrospectively included a consecutive cohort of surgical patients who had negative preoperative MRIs. MAP was performed on T1-weighted sequence and QPET was performed on PET/CT data, both with comparison to scanner-specific normal databases. Review and analysis of MAP and QPET were performed blinded to patients’ clinical information. Concordance between MAP and QPET was assessed on a lobar level and the significance of concordant QPET-MAP+ abnormalities was confirmed by seizure outcome and histopathological confirmation. Results: A total of 104 patients were included. Complete resection of the QPET-MAP+ region was significantly associated with seizure-free outcome when compared with the partial resection group (p=0.023, p < 0.001, p= 0.006) or the no resection group (p=0.002, p < 0.001, p=0.001), at QPET thresholds of standard deviations (SD) -1, -2, and -3, respectively. The SD threshold of -2 showed the best combination of positive rate (55%), sensitivity (0.68), specificity (0.88), positive predictive value (0.88) and negative predictive value (0.69). Surgical pathology of the resected QPET-MAP+ areas contained mainly focal cortical dysplasia (FCD) type I. Multiple QPET-MAP+ regions were present in 12% of the patients at SD=-2. Conclusions: This study demonstrates that combining quantitative analyses of functional (QPET) and structural (MAP) imaging data improves identification of potentially epileptogenic abnormalities, which may lead to more favorable post-resective seizure outcomes in “non-lesional” epilepsies. Funding: No Funding
Neuroimaging