Validation of FreeSurfer-estimated brain cortical thickness: comparison with histologic measurements.
FreeSurfer software package automatically estimates the cerebral cortical thickness. Its use is widely accepted, albeit this tool was validated against histologic measurements in only two post-mortem isolated brain MR scans. Indeed, a comparison between histologic measurements and FreeSurfer estimation from in vivo data was never performed. At the "Claudio Munari" Center for Epilepsy and Parkinson Surgery we have included FreeSurfer in our presurgical workflow since 2008, mainly because the automatic reconstruction of the brain surface is useful for carefully planning the surgical resection. We therefore compared cortical thickness values obtained by the automatic software pipeline with manual histologic measurements performed on 27 histologic specimens resected from the corresponding brain regions of the same epileptic subjects. This method-comparison study, including Passing-Bablok regression and Bland-Altman plot analysis, showed a good agreement between FreeSurfer estimation and histologic measurements of cortical thickness. The mean cortical thickness values (±Standard Deviation) obtained with FreeSurfer and histologic measurements were 3.65 mm ± 0.44 and 3.72 mm ± 0.36, respectively (P value = 0.32). Our findings strengthen previous reports on cortical thickness changes as biomarkers of different neurological conditions.
"Claudio Munari" Center for Epilepsy and Parkinson Surgery, Niguarda Hospital, Piazza Ospedale Maggiore, 3, 20162, Milan, Italy, francesco.cardinale@ospedaleniguarda.it.
Francesco
F
Cardinale
Giuseppa
G
Chinnici
Manuela
M
Bramerio
Roberto
R
Mai
Ivana
I
Sartori
Massimo
M
Cossu
Giorgio
G
Lo Russo
Laura
L
Castana
Nadia
N
Colombo
Chiara
C
Caborni
Elena
E
De Momi
Giancarlo
G
Ferrigno
D000293:Adolescent; D000328:Adult; D002540:Cerebral Cortex / Q000033:anatomy & histology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006653:Histology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging / Q000379:methods*; D015203:Reproducibility of Results; D012986:Software Validation; D055815:Young Adult