An evaluation of the diagnostic equivalence of 18F-FDG-PET between hybrid PET/MRI and PET/CT in drug-resistant epilepsy: A pilot study

Stefan E Poirier; Benjamin Y M Kwan; Michael T Jurkiewicz; Lina Samargandy; Maryssa Iacobelli; David A Steven; Victor Lam Shin Cheung; Gerald Moran; Frank S Prato; R Terry Thompson; Jorge G Burneo; Udunna C Anazodo; Jonathan D Thiessen

doi:10.1016/j.eplepsyres.2021.106583

An evaluation of the diagnostic equivalence of ¹⁸F-FDG-PET between hybrid PET/MRI and PET/CT in drug-resistant epilepsy: A pilot study

Epilepsy Res. 2021 May:172:106583. doi: 10.1016/j.eplepsyres.2021.106583. Epub 2021 Feb 16.

Affiliations

¹ Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada. Electronic address: [email protected].
² Department of Diagnostic Radiology, Queen's University, Kingston, ON, Canada.
³ Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
⁴ Lawson Imaging, Lawson Health Research Institute, London, ON, Canada.
⁵ Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
⁶ Siemens Healthineers, Oakville, ON, Canada.
⁷ Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Medical Imaging, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada.
⁸ Lawson Imaging, Lawson Health Research Institute, London, ON, Canada; Department of Medical Biophysics, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada; Research Centre for Studies in Aging, McGill University, Montréal, QC, Canada. Electronic address: [email protected].

PMID: 33636504
DOI: 10.1016/j.eplepsyres.2021.106583

Abstract

Objective: Hybrid PET/MRI may improve detection of seizure-onset zone (SOZ) in drug-resistant epilepsy (DRE), however, concerns over PET bias from MRI-based attenuation correction (MRAC) have limited clinical adoption of PET/MRI. This study evaluated the diagnostic equivalency and potential clinical value of PET/MRI against PET/CT in DRE.

Materials and methods: MRI, FDG-PET and CT images (n = 18) were acquired using a hybrid PET/MRI and a CT scanner. To assess diagnostic equivalency, PET was reconstructed using MRAC (RESOLUTE) and CT-based attenuation correction (CTAC) to generate PET/MRI and PET/CT images, respectively. PET/MRI and PET/CT images were compared qualitatively through visual assessment and quantitatively through regional standardized uptake value (SUV) and z-score assessment. Diagnostic accuracy and sensitivity of PET/MRI and PET/CT for SOZ detection were calculated through comparison to reference standards (clinical hypothesis and histopathology, respectively).

Results: Inter-reader agreement in visual assessment of PET/MRI and PET/CT images was 78 % and 81 %, respectively. PET/MRI and PET/CT were strongly correlated in mean SUV (r = 0.99, p < 0.001) and z-scores (r = 0.92, p < 0.001) across all brain regions. MRAC SUV bias was <5% in most brain regions except the inferior temporal gyrus, temporal pole, and cerebellum. Diagnostic accuracy and sensitivity were similar between PET/MRI and PET/CT (87 % vs. 85 % and 83 % vs. 83 %, respectively).

Conclusion: We demonstrate here that PET/MRI with optimal MRAC can yield similar diagnostic performance as PET/CT. Nevertheless, further exploration of the potential added value of PET/MRI is necessary before clinical adoption of PET/MRI for epilepsy imaging.

Keywords: Drug-resistant epilepsy; Fluorodeoxyglucose; MRI-based attenuation correction; PET/CT; PET/MRI.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Drug Resistant Epilepsy* / diagnostic imaging
Epilepsy*
Fluorodeoxyglucose F18
Humans
Magnetic Resonance Imaging
Multimodal Imaging
Pharmaceutical Preparations*
Pilot Projects
Positron Emission Tomography Computed Tomography
Positron-Emission Tomography

Substances

Pharmaceutical Preparations
Fluorodeoxyglucose F18