Combined Ex Vivo 9.4T MRI and Quantitative Histopathological Study in Normal and Pathological Neocortical Resections in Focal Epilepsy.
High-resolution magnetic resonance imaging (MRI) may improve the preoperative diagnosis of focal cortical dysplasia (FCD) in epilepsy. Quantitative 9.4T MRI was carried out (T1, T2, T2* and magnetization transfer ratio) on 13 cortical resections, representing pathologically confirmed FCD (five cases) and normal cortex. Quantitative immunohistochemistry for myelination (myelin basic protein/SMI94), neuronal populations [microtubule-associated protein 2 (MAP2), neurofilament (SMI31, SMI32), synaptophysin, NeuN, calbindin], reactive glia (GFAP), microglia (CD68) and blood-brain barrier permeability (albumin) was carried out in 43 regions of interest (ROI) from normal and abnormal white matter and cortex. MRI was spatially aligned and quantitative analysis carried out on corresponding ROI. Line profile analysis (LPA) of intensity gradients through the cortex was carried out on MRI and immunostained sections. An inverse correlation was noted between myelin/SMI94 and T1, T2 (P < 0.005) and T2* (P < 0.05; Spearman's correlation) and a positive correlation between neuronal MAP2 and T1 (P < 0.005) and T2* (P < 0.05) over all ROI. Similar pathology-MRI correlations were observed for histologically unremarkable white matter ROI only. LPA showed altered gradient contours in regions of FCD, reflecting abnormal cortical lamination and myelo-architecture, including a preoperatively undetected FCD case. This study demonstrates the ability of quantitative 9.4T MRI to detect subtle differences in neuronal numbers and myelination in histologically normal appearing white matter and LPA in the evaluation of cortical dyslamination. These methods may be translatable to the in vivo detection of mild cortical malformations.
Department of Neuropathology, UCL, Institute of Neurology, London, UK.|Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Cheryl
C
Reeves
Department of Neuroradiology, UCL, Institute of Neurology, London, UK.|Department of Brain Repair and Rehabilitation, UCL, Institute of Neurology, London, UK.
Mohamed
M
Tachrount
Department of Brain Repair and Rehabilitation, UCL, Institute of Neurology, London, UK.
David
D
Thomas
Department of Neuropathology, UCL, Institute of Neurology, London, UK.|Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Zuzanna
Z
Michalak
Department of Neuropathology, UCL, Institute of Neurology, London, UK.|Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Joan
J
Liu
Department of Neuropathology, UCL, Institute of Neurology, London, UK.
Matthew
M
Ellis
Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Beate
B
Diehl
Department of Neurosurgery, UCL, Institute of Neurology, London, UK.
Anna
A
Miserocchi
Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.|Department of Neurosurgery, UCL, Institute of Neurology, London, UK.
Andrew W
AW
McEvoy
Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Sofia
S
Eriksson
Department of Neuroradiology, UCL, Institute of Neurology, London, UK.|Department of Brain Repair and Rehabilitation, UCL, Institute of Neurology, London, UK.
Tarek
T
Yousry
Department of Neuropathology, UCL, Institute of Neurology, London, UK.|Department of Clinical and Experimental Epilepsy, UCL, Institute of Neurology, London, UK.
Maria
M
Thom
D000328:Adult; D004828:Epilepsies, Partial / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019579:Neocortex / Q000000981:diagnostic imaging* / Q000473:pathology; D066127:White Matter / Q000000981:diagnostic imaging / Q000473:pathology; D055815:Young Adult
9.4T MRI; dysplasia; focal epilepsy; quantitative neuropathology