title: Hippocampal subfields at ultra high field MRI: An overview of segmentation and measurement methods.
abstract: The hippocampus is one of the most interesting and studied brain regions because of its involvement in memory functions and its vulnerability in pathological conditions, such as neurodegenerative processes. In the recent years, the increasing availability of Magnetic Resonance Imaging (MRI) scanners that operate at ultra-high field (UHF), that is, with static magnetic field strength ≥7T, has opened new research perspectives. Compared to conventional high-field scanners, these systems can provide new contrasts, increased signal-to-noise ratio and higher spatial resolution, thus they may improve the visualization of very small structures of the brain, such as the hippocampal subfields. Studying the morphometry of the hippocampus is crucial in neuroimaging research because changes in volume and thickness of hippocampal subregions may be relevant in the early assessment of pathological cognitive decline and Alzheimer's Disease (AD). The present review provides an overview of the manual, semi-automated and fully automated methods that allow the assessment of hippocampal subfield morphometry at UHF MRI, focusing on the different hippocampal segmentation produced. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Physics, University of Pisa, Pisa, Italy.|National Institute of Nuclear Physics (INFN), Pisa Division, Pisa, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Giuliano
authors.affiliation: Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
authors.forename: Graziella
authors.initials: G
authors.lastname: Donatelli
authors.affiliation: Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy.
authors.forename: Mirco
authors.initials: M
authors.lastname: Cosottini
authors.affiliation: Laboratory of Medical Physics and Biotechnologies for Magnetic Resonance, IRCCS Stella Maris Foundation, Pisa, Italy; Imago7 Foundation, Pisa, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Tosetti
authors.affiliation: National Institute of Nuclear Physics (INFN), Pisa Division, Pisa, Italy.
authors.forename: Alessandra
authors.identifier: http://orcid.org/0000-0001-5135-4472
authors.initials: A
authors.lastname: Retico
authors.affiliation: Department of Physics, University of Pisa, Pisa, Italy.
authors.forename: Maria Evelina
authors.initials: ME
authors.lastname: Fantacci
mesh_terms: D006624:Hippocampus / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*
keywords: hippocampal subfields; morphometry; quantification; segmentation; ultra-high field MRI