MRI characteristics of the glia limitans externa: A 7T study
| Autor: | Tsutomu Nakada, Kazunori Nakada, Ingrid L. Kwee, Masaki Watanabe, Kiyotaka Suzuki, Yuji Suzuki, Kenichi Yamada |
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| Rok vydání: | 2017 |
| Předmět: |
Adult
Male 0301 basic medicine media_common.quotation_subject Biomedical Engineering Biophysics Fluid-attenuated inversion recovery Young Adult 03 medical and health sciences 0302 clinical medicine Nuclear magnetic resonance Humans Contrast (vision) Radiology Nuclear Medicine and imaging Cluster analysis media_common Cerebral Cortex Physics Glia limitans Anatomy Magnetic Resonance Imaging Independent component analysis 030104 developmental biology Water channel Blood-Brain Barrier Microscopic imaging T2 weighted 030217 neurology & neurosurgery |
| Zdroj: | Magnetic Resonance Imaging. 44:140-145 |
| ISSN: | 0730-725X |
| Popis: | Purpose To perform a systematic analysis of the intrinsic contrast parameters of the FLAIR hyperintense rim (FHR), a thin layer of high intensity covering the entire surface of the cerebral cortex detected on fluid-attenuated inversion recovery (FLAIR) sequence T2 weighted imaging performed on a 7T system, in an attempt to identify its anatomical correlate. Methods Fast spin echo inversion recovery (FSE-IR) and cardiac-gated fast spin echo (FSE) images were obtained with defined parameters in eight normal volunteers on a 7 T MRI system to determine T2 and proton density, T1 characteristics. K-means clustering analysis of parameter sets was performed using MATLAB version R2015b for the purpose of identifying the cluster reflecting FHR. The results were subsequently confirmed by independent component analysis (ICA) based on T1 behavior on FSE-IR using a MATLAB script of FastICA algorithm. Results The structure giving rise to FHR was found to have a unique combination of intrinsic contrast parameters of low proton density, long T2, and disproportionally short T1. The findings are in strong agreement with the functional and structural specifics of the glia limitans externa (GLE), a structure composed of snuggled endfeet of astrocytes containing abundant aquaporin-4 (AQP-4), the main water channel of the brain. Conclusion Intrinsic contrast parameters of FHR reflect structural and functional specifics of the GLE, and their values are highly dependent on the physiologic functionality of AQP-4. Microscopic imaging on a 7T system and analysis of GLE contrast parameters can be developed into a method for evaluating AQP-4 functionality. |
| Databáze: | OpenAIRE |
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