This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objectives: The purpose of the study was to investigate the abnormalities of cortical lamination observed in temporal lobe specimens obtained during surgery for intractable temporal lobe epilepsy (TLE) with hippocampal sclerosis. Specifically, we aimed to 1) correlate high-field ex vivo MRI with histopathologic analysis and 2) evaluate the effect of tissue fixation on image contrast.
Methods: A cohort of 13 specimens was considered. T2-weighted imaging and relaxometry were performed during and after fixation using a 7-T experimental scanner. After imaging, the specimens were studied with histopathologic (Black Gold myelin fiber staining) and immunohistochemical (NeuN neuronal staining) methods in order to explore the correspondence between MRI and histopathologic features.
Results: The principal findings of this study are that 1) superior MRI contrast is obtained among the cortical layers using completely fixed specimens as opposed to recently excised tissue, 2) the intensity of the T2-weighted MRI signal is lowest (hypointensity) at the site of highest fiber concentration and cellular density, and highest (hyperintensity) when the density of fibers and cells is lowest, and 3) the MRI signal is altered in presence of abnormal cortical lamination (focal cortical dysplasia type IA).
Conclusions: High resolution ex vivo MRI enables the study of intracortical organization in normal and pathologic areas. Comparisons between MRI, NeuN, and Black Gold indicate that the differences apparent in T2-weighted images are mainly related to fiber concentration, although neuronal density might also play a role.
Footnotes
-
Study funding: Supported by grants from the Italian Ministry of Health, Associazione Paolo Zorzi, Fondazione Banca del Monte di Lombardia (FBML), and EU grant “Functional Genomics and Neurobiology of Epilepsy (EPICURE)” contract LSHM-CT-2006.0373315.
-
Supplemental data at www.neurology.org
-
- FCD
- focal cortical dysplasia
- HS
- hippocampal sclerosis
- MR
- magnetic resonance
- TE
- echo time
- TLE
- temporal lobe epilepsy
- TR
- repetition time
- Received July 29, 2010.
- Accepted December 22, 2010.
- Copyright © 2011 by AAN Enterprises, Inc.
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Disputes & Debates: Rapid online correspondence
NOTE: All authors' disclosures must be entered and current in our database before comments can be posted. Enter and update disclosures at http://submit.neurology.org. Exception: replies to comments concerning an article you originally authored do not require updated disclosures.
- Stay timely. Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- 200 words maximum.
- 5 references maximum. Reference 1 must be the article on which you are commenting.
- 5 authors maximum. Exception: replies can include all original authors of the article.
- Submitted comments are subject to editing and editor review prior to posting.