Validation of FDG‐PET/MRI coregistration in nonlesional refractory childhood epilepsy

• Published in: Epilepsia (Copenhagen) 2011-12, Vol.52 (12), p.2216-2224
• Main Authors: Rubí, Sebastià, Setoain, Xavier, Donaire, Antonio, Bargalló, Núria, Sanmartí, Francesc, Carreño, Mar, Rumià, Jordi, Calvo, Anna, Aparicio, Javier, Campistol, Jaume, Pons, Francesca
• Format: Article
• Language: English
• Subjects: Adolescent; Anticonvulsants. Antiepileptics. Antiparkinson agents; Biological and medical sciences; Brain - diagnostic imaging; Brain - pathology; Brain Mapping; Child; Child, Preschool; Children; Data processing; Electroencephalography - methods; Epilepsy; Epilepsy - diagnosis; Epilepsy - physiopathology; FDG‐PET; Female; Fluorodeoxyglucose F18; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medical imaging; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Neuropharmacology; NMR; Nuclear magnetic resonance; Pediatrics; Pharmacology. Drug treatments; Positron-Emission Tomography - methods
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2011.03295.x

Summary Purpose:  To validate the use of 18F‐fluorodeoxyglucose–positron emission tomography/magnetic resonance imaging (FDG‐PET/MRI) coregistration for epileptogenic zone detection in children with MRI nonlesional refractory epilepsy and to assess its ability to guide a second interpretation of the MRI studies. Methods:  Thirty‐one children with refractory epilepsy whose MRI results were nonlesional were included prospectively. All patients underwent presurgical evaluation following the standard protocol of our epilepsy unit, which included FDG‐PET and FDG‐PET/MRI coregistration. Cerebral areas of decreased uptake in PET and PET/MRI fusion images were compared visually and then contrasted with presumed epileptogenic zone localization, which had been obtained from other clinical data. A second interpretation of MRI studies was carried out, focusing on the exact anatomic region in which hypometabolism was located in FDG‐PET/MRI fusion images. Key Findings:  Both FDG‐PET and FDG‐PET/MRI detected hypometabolism in 67.8% of patients, with good concordance on a subject basis and on the cerebral region involved (κ statistic = 0.83 and 0.79, respectively). Hypometabolism detected by single PET, as well as by PET/MRI fusion images, was located in the same hemisphere, as indicated by electroclinical data in 58% of patients, and at the same place in 39% of cases. Of the patients who showed hypometabolism on PET/MRI, 43% also experienced changes in the guided second MRI interpretation, from nonlesional to subtle‐lesional. Significance:  PET/MRI coregistration is an imaging variant that is at least as accurate as PET alone in detecting epileptogenic zone in pediatric nonlesional patients, and can guide a second look at MRI studies previously reported as nonlesional, turning a meaningful percentage into subtle‐lesional.