title: Advanced diffusion imaging sequences could aid assessing patients with focal cortical dysplasia and epilepsy.
abstract: Malformations of cortical development (MCD), particularly focal cortical dysplasia (FCD), are a common cause of refractory epilepsy but are often invisible on structural imaging. NODDI (neurite orientation dispersion and density imaging) is an advanced diffusion imaging technique that provides additional information on tissue microstructure, including intracellular volume fraction (ICVF), a marker of neurite density. We applied this technique in 5 patients with suspected dysplasia to show that the additional parameters are compatible with the underlying disrupted tissue microstructure and could assist in the identification of the affected area. The consistent finding was reduced ICVF in the area of dysplasia. In one patient, an area of reduced ICVF and increased fibre dispersion was identified that was not originally seen on the structural imaging. The focal reduction in ICVF on imaging is compatible with previous iontophoretic data in surgical specimens, was more conspicuous than on other clinical or diffusion images (supported by an increased contrast-to-noise ratio) and more localised than on previous DTI studies. NODDI may therefore assist the clinical identification and localisation of FCD in patients with epilepsy. Future studies will assess this technique in a larger cohort including MRI negative patients.
authors: Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: g.winston@ucl.ac.uk.
authors: Gavin P
authors: GP
authors: Winston
authors: Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: caroline.micallef@uclh.nhs.uk.
authors: Caroline
authors: C
authors: Micallef
authors: Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: m.symms@ucl.ac.uk.
authors: Mark R
authors: MR
authors: Symms
authors: Department of Computer Science & Centre for Medical Image Computing, University College London, Gower Street, London WC1E 6BT, United Kingdom. Electronic address: d.alexander@ucl.ac.uk.
authors: Daniel C
authors: DC
authors: Alexander
authors: Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: j.duncan@ucl.ac.uk.
authors: John S
authors: JS
authors: Duncan
authors: Department of Computer Science & Centre for Medical Image Computing, University College London, Gower Street, London WC1E 6BT, United Kingdom. Electronic address: gary.zhang@ucl.ac.uk.
authors: Hui
authors: H
authors: Zhang
mesh_terms: D000328:Adult; D056324:Diffusion Tensor Imaging / Q000379:methods / Q000592:standards*; D004827:Epilepsy / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications* / Q000175:diagnosis*; D008875:Middle Aged; D055815:Young Adult
keywords: Diffusion imaging; Epilepsy surgery; Focal cortical dysplasia; NODDI; Neurite density