title: Resolution considerations in imaging of the cortical layers.
abstract: The cortical layers are a finger print of brain development, function, connectivity and pathology. Obviously, the formation of the layers and their composition is essential to cognition and behavior. The layers were traditionally measured by histological means but recent studies utilizing MRI suggested that T1 relaxation imaging consist of enough contrast to separate the layers. Indeed extreme resolution, post mortem, studies demonstrated this phenomenon. Yet, one of the limiting factors of using T1 MRI to visualize the layers in neuroimaging research is partial volume effect. This happen when the image resolution is not high enough and two or more layers resides within the same voxel. In this paper we demonstrate that due to the physical small thickness of the layers it is highly unlikely that high resolution imaging could resolve the layers. By contrast, we suggest that low resolution multi T1 mapping conjugate with composition analysis could provide practical means for measuring the T1 layers. We suggest an acquisition platform that is clinically feasible and could quantify measures of the layers. The key feature of the suggested platform is that separation of the layers is better achieved in the T1 relaxation domain rather than in the spatial image domain.
authors.affiliation: Department of Statistics and Operations Research, Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Shlomi
authors.initials: S
authors.lastname: Lifshits
authors.affiliation: Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Omri
authors.initials: O
authors.lastname: Tomer
authors.affiliation: Department of mechanical engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Ittai
authors.initials: I
authors.lastname: Shamir
authors.affiliation: The Strauss Center for Computational Neuroimaging, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Barazany
authors.affiliation: Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, Ramat Gan, Israel.
authors.forename: Galia
authors.initials: G
authors.lastname: Tsarfaty
authors.affiliation: Department of Statistics and Operations Research, Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv, Israel.
authors.forename: Saharon
authors.initials: S
authors.lastname: Rosset
authors.affiliation: Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel; Department of Neurobiology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel. Electronic address: assafyan@gmail.com.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Assaf
mesh_terms: D000328:Adult; D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D051381:Rats
keywords: Brain parcellation; Cortical layers; MRI resolution; Partial volume effect; T1 relaxation