title: Volume estimation of the thalamus using freesurfer and stereology: consistency between methods.
abstract: Freely available automated MR image analysis techniques are being increasingly used to investigate neuroanatomical abnormalities in patients with neurological disorders. It is important to assess the specificity and validity of automated measurements of structure volumes with respect to reliable manual methods that rely on human anatomical expertise. The thalamus is widely investigated in many neurological and neuropsychiatric disorders using MRI, but thalamic volumes are notoriously difficult to quantify given the poor between-tissue contrast at the thalamic gray-white matter interface. In the present study we investigated the reliability of automatically determined thalamic volume measurements obtained using FreeSurfer software with respect to a manual stereological technique on 3D T1-weighted MR images obtained from a 3 T MR system. Further to demonstrating impressive consistency between stereological and FreeSurfer volume estimates of the thalamus in healthy subjects and neurological patients, we demonstrate that the extent of agreeability between stereology and FreeSurfer is equal to the agreeability between two human anatomists estimating thalamic volume using stereological methods. Using patients with juvenile myoclonic epilepsy as a model for thalamic atrophy, we also show that both automated and manual methods provide very similar ratios of thalamic volume loss in patients. This work promotes the use of FreeSurfer for reliable estimation of global volume in healthy and diseased thalami.
authors.affiliation: Department of Neurology, University of Münster, Münster, Germany.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Keller
authors.forename: Jan S
authors.initials: JS
authors.lastname: Gerdes
authors.forename: Siawoosh
authors.initials: S
authors.lastname: Mohammadi
authors.forename: Christoph
authors.initials: C
authors.lastname: Kellinghaus
authors.forename: Harald
authors.initials: H
authors.lastname: Kugel
authors.forename: Katja
authors.initials: K
authors.lastname: Deppe
authors.forename: E Bernd
authors.initials: EB
authors.lastname: Ringelstein
authors.forename: Stefan
authors.initials: S
authors.lastname: Evers
authors.forename: Wolfram
authors.initials: W
authors.lastname: Schwindt
authors.forename: Michael
authors.initials: M
authors.lastname: Deppe
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001284:Atrophy / Q000209:etiology / Q000473:pathology; D001931:Brain Mapping; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020190:Myoclonic Epilepsy, Juvenile / Q000150:complications / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D012984:Software; D013238:Stereotaxic Techniques / Q000295:instrumentation; D013788:Thalamus / Q000473:pathology*; D055815:Young Adult