title: A Semiautomatic Method for Multiple Sclerosis Lesion Segmentation on Dual-Echo MR Imaging: Application in a Multicenter Context.
abstract: OBJECTIVE
  The automatic segmentation of MS lesions could reduce time required for image processing together with inter- and intraoperator variability for research and clinical trials. A multicenter validation of a proposed semiautomatic method for hyperintense MS lesion segmentation on dual-echo MR imaging is presented.
  
  
  METHODS
  The classification technique used is based on a region-growing approach starting from manual lesion identification by an expert observer with a final segmentation-refinement step. The method was validated in a cohort of 52 patients with relapsing-remitting MS, with dual-echo images acquired in 6 different European centers.
  
  
  RESULTS
  We found a mathematic expression that made the optimization of the method independent of the need for a training dataset. The automatic segmentation was in good agreement with the manual segmentation (dice similarity coefficient = 0.62 and root mean square error = 2 mL). Assessment of the segmentation errors showed no significant differences in algorithm performance between the different MR scanner manufacturers (P> .05).
  
  
  CONCLUSIONS
  The method proved to be robust, and no center-specific training of the algorithm was required, offering the possibility for application in a clinical setting. Adoption of the method should lead to improved reliability and less operator time required for image analysis in research and clinical trials in MS.
authors.affiliation: From the Neuroimaging Research Unit (L.S., E.P., M.A.R., P.P., M.F.).
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-4979-613X
authors.initials: L
authors.lastname: Storelli
authors.affiliation: From the Neuroimaging Research Unit (L.S., E.P., M.A.R., P.P., M.F.).
authors.forename: E
authors.identifier: http://orcid.org/0000-0002-1850-1175
authors.initials: E
authors.lastname: Pagani
authors.affiliation: From the Neuroimaging Research Unit (L.S., E.P., M.A.R., P.P., M.F.).|Institute of Experimental Neurology, Division of Neuroscience, Department of Neurology (M.A.R., P.P., M.F.), San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: M A
authors.identifier: http://orcid.org/0000-0003-2358-4320
authors.initials: MA
authors.lastname: Rocca
authors.affiliation: Xinapse Systems (M.A.H.), Colchester, United Kingdom.
authors.forename: M A
authors.identifier: http://orcid.org/0000-0002-0815-6697
authors.initials: MA
authors.lastname: Horsfield
authors.affiliation: MRI Center "SUN-FISM" and Institute of Diagnosis and Care "Hermitage-Capodimonte" (A.G., A.B.).|I Division of Neurology, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences (A.G., A.B.), Second University of Naples, Naples, Italy.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-2203-6237
authors.initials: A
authors.lastname: Gallo
authors.affiliation: MRI Center "SUN-FISM" and Institute of Diagnosis and Care "Hermitage-Capodimonte" (A.G., A.B.).|I Division of Neurology, Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences (A.G., A.B.), Second University of Naples, Naples, Italy.
authors.forename: A
authors.identifier: http://orcid.org/0000-0002-7202-4445
authors.initials: A
authors.lastname: Bisecco
authors.affiliation: Department of Neurological and Behavioral Sciences (M.B., N.D.S.), University of Siena, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-9188-4408
authors.initials: M
authors.lastname: Battaglini
authors.affiliation: Department of Neurological and Behavioral Sciences (M.B., N.D.S.), University of Siena, Italy.
authors.forename: N
authors.identifier: http://orcid.org/0000-0003-4930-7639
authors.initials: N
authors.lastname: De Stefano
authors.affiliation: Department of Radiology and Nuclear Medicine, MS Centre Amsterdam (H.V.), VU Medical Centre, Amsterdam, the Netherlands.
authors.forename: H
authors.identifier: http://orcid.org/0000-0001-9106-1172
authors.initials: H
authors.lastname: Vrenken
authors.affiliation: Neuroradiological Academic Unit (D.L.T., L.M.), UCL Institute of Neurology, London, United Kingdom.
authors.forename: D L
authors.identifier: http://orcid.org/0000-0003-1491-1641
authors.initials: DL
authors.lastname: Thomas
authors.affiliation: Neuroradiological Academic Unit (D.L.T., L.M.), UCL Institute of Neurology, London, United Kingdom.
authors.forename: L
authors.identifier: http://orcid.org/0000-0002-4596-3551
authors.initials: L
authors.lastname: Mancini
authors.affiliation: Department of Neurology (S.R., C.E.).
authors.forename: S
authors.identifier: http://orcid.org/0000-0002-5559-768X
authors.initials: S
authors.lastname: Ropele
authors.affiliation: Department of Neurology (S.R., C.E.).|Clinical Division of Neuroradiology, Vascular and Interventional Radiology, Department of Radiology (C.E.), Medical University of Graz, Austria.
authors.forename: C
authors.identifier: http://orcid.org/0000-0001-9764-7617
authors.initials: C
authors.lastname: Enzinger
authors.affiliation: From the Neuroimaging Research Unit (L.S., E.P., M.A.R., P.P., M.F.).|Institute of Experimental Neurology, Division of Neuroscience, Department of Neurology (M.A.R., P.P., M.F.), San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: P
authors.identifier: http://orcid.org/0000-0002-7826-0019
authors.initials: P
authors.lastname: Preziosa
authors.affiliation: From the Neuroimaging Research Unit (L.S., E.P., M.A.R., P.P., M.F.) filippi.massimo@hsr.it.|Institute of Experimental Neurology, Division of Neuroscience, Department of Neurology (M.A.R., P.P., M.F.), San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
authors.forename: M
authors.identifier: http://orcid.org/0000-0002-5485-0479
authors.initials: M
authors.lastname: Filippi