Survey of Protocols for the Manual Segmentation of the Hippocampus: Preparatory Steps Towards a Joint EADC-ADNI Harmonized Protocol

Issue title: Imaging the Alzheimer Brain

Guest editors: J. Wesson Ashford, Allyson Rosen, Maheen Adamson, Peter Bayley, Osama Sabri, Ansgar Furst, Sandra E. Black and Michael Weiner

Article type: Research Article

Authors: Boccardi, Marina^a | Ganzola, Rossana^a | Bocchetta, Martina^a | Pievani, Michela^a | Redolfi, Alberto^a | Bartzokis, George^b | Camicioli, Richard^c | Csernansky, John G.^d | de Leon, Mony J.^e | deToledo-Morrell, Leyla^f | Killiany, Ronald J.^g | Lehéricy, Stéphane^h | Pantel, Johannesⁱ | Pruessner, Jens C.^j | Soininen, H.^k | Watson, Craig^l | Duchesne, Simon^m | Jack Jr, Clifford R.ⁿ | Frisoni, Giovanni B.^{a; *}

Affiliations: [a] LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine) IRCCS – S. Giovanni di Dio – Fatebenefratelli Brescia, Italy | [b] Department of Psychiatry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA | [c] Department of Biomedical Engineering, Centre for Neuroscience, University of Alberta, Edmonton, AB, Canada | [d] Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL, USA | [e] Center for Brain Health, New York University School of Medicine, New York, NY, USA | [f] Department of Neurological Sciences, Rush University, Chicago, IL, USA | [g] Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, USA | [h] Center for NeuroImaging Research - CENIR and Dept of Neuroradiology, Université Pierre et Marie Curie-Paris 6, Groupe Hospitalier Pitié-Salpêtrière, Paris, France | [i] Department of Psychiatry and Psychoterapy, University of Frankfurt/Main, Germany | [j] McGill Centre for Studies in Aging, Department of Psychiatry, McGill University, Montreal, Quebec, Canada | [k] Department of Neurology, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland | [l] Department of Neurology, Wayne State University School of Medicine, 8D-University Health Center, St. Antoine, Detroit, MI, USA | [m] Department of Radiology, Université Laval and Centre de Recherche Université Laval – Robert Giffard, Quebec City, Canada | [n] Department of Diagnostic Radiology, Mayo Clinic and Foundation, Rochester, MN, USA

Correspondence: [*] Correspondence to: Giovanni B. Frisoni, LENITEM, IRCCS S.Giovanni di Dio, via Pilastroni, 4, 25100 Brescia – Italy, Tel.: +39 030 3501361; Fax: +39 02 700435727; E-mail: [email protected].

Abstract: Manual segmentation from magnetic resonance imaging (MR) is the gold standard for evaluating hippocampal atrophy in Alzheimer's disease (AD). Nonetheless, different segmentation protocols provide up to 2.5-fold volume differences. Here we surveyed the most frequently used segmentation protocols in the AD literature as a preliminary step for international harmonization. The anatomical landmarks (anteriormost and posteriormost slices, superior, inferior, medial, and lateral borders) were identified from 12 published protocols for hippocampal manual segmentation ([Abbreviation] first author, publication year: [B] Bartzokis, 1998; [C] Convit, 1997; [dTM] deToledo-Morrell, 2004; [H] Haller, 1997; [J] Jack, 1994; [K] Killiany, 1993; [L] Lehericy, 1994; [M] Malykhin, 2007; [Pa] Pantel, 2000; [Pr] Pruessner, 2000; [S] Soininen, 1994; [W] Watson, 1992). The hippocampi of one healthy control and one AD patient taken from the 1.5T MR ADNI database were segmented by a single rater according to each protocol. The accuracy of the protocols' interpretation and translation into practice was checked with lead authors of protocols through individual interactive web conferences. Semantically harmonized landmarks and differences were then extracted, regarding: (a) the posteriormost slice, protocol [B] being the most restrictive, and [H, M, Pa, Pr, S] the most inclusive; (b) inclusion [C, dTM, J, L, M, Pr, W] or exclusion [B, H, K, Pa, S] of alveus/fimbria; (c) separation from the parahippocampal gyrus, [C] being the most restrictive, [B, dTM, H, J, Pa, S] the most inclusive. There were no substantial differences in the definition of the anteriormost slice. This survey will allow us to operationalize differences among protocols into tracing units, measure their impact on the repeatability and diagnostic accuracy of manual hippocampal segmentation, and finally develop a harmonized protocol.

Keywords: Hippocampus, manual segmentation protocol, harmonization, anatomical landmark, Alzheimer's disease, manual tracing, medial temporal lobes, atrophy, degeneration, MRI

DOI: 10.3233/JAD-2011-0004

Journal: Journal of Alzheimer's Disease, vol. 26, no. s3, pp. 61-75, 2011