Contributions
Abstract: EP1520
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Background: Hippocampal atrophy occurs in Multiple Sclerosis (MS) patients since the early disease stages and has been associated with the impairment of episodic, visuospatial and verbal memory. Despite the growing clinical interest, Magnetic Resonance Imaging (MRI) derived measures of the hippocampal volume (HipV) from large datasets are missing, with important limitations for the implementation of this measure in large clinical studies.
Objective: To assess normative data of the HipV in healthy subjects (HS) on a large cross-sectional MRI dataset to be used as a reference in clinical studies.
Materials: The HipV of 727 HS was assessed from freely available MRI datasets. The age at scan-time ranged from 20 to 80 years. Data were stratified for gender and magnetic field strength (1.5 and 3 T). Volumes were obtained using a semi-automated approach, based on the manual editing of the masks obtained with FIRST (fsl.fmrib.ox.ac.uk/fsl/fslwiki/FIRST). In 100 MRI scans, the accuracy of the method was compared with a fully manual segmentation output and with the fully automated outputs from FIRST and FreeSurfer. Finally, a multivariate regression using HipV corrected for head size as dependent variable and gender and age and their interactions as predictors was performed.
Results: Volume masks from our semi-automated approach were very similar to those obtained with the fully manual approach (7.1±0.7 cm3 vs 7.1±0.6 cm3, p=0.98; DICE=0.92) and significantly lower than those obtained fully automatically with FreeSurfer (8.5±0.94 cm3, p< 0.001; DICE=0.8) and FIRST (8.2±0.83 cm3, p< 0.001; DICE=0.88). Age, quadratic age and gender were the predictors better fitting HipVs (R2=0.164, p< 0.001). Due to the dependence on gender, females showed constantly larger HipV with respect to males (0.44 cm3, p< 0.0001). Due to the dependence on age, HipV decreased by 0.07% per year between 25 and 55 years of age (Hip female at 25 years: 9.9 cm3; at 55 years: 9.7 cm3), with an apparent acceleration (0.51% per year) between 55 and 85 years of age (Hip female at 85 years: 8.2 cm3).
Discussion: The study provides normative data of HipV over the adult life-span for males and females to be used as reference in MS studies at group and individual levels.
Disclosure:
L. Luchetti, G. Gentile, M. Battaglini, A. Giorgio have nothing to declare
N. De Stefano has received honoraria from Biogen-Idec, Genzyme, Merck Serono, Novartis, Roche and Teva for consulting services, speaking and travel support. He serves on advisory boards for Merck Serono, Novartis, Biogen-Idec, Roche, and Genzyme, he has received research grant support from the Italian MS Society.
Abstract: EP1520
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 21 Imaging
Background: Hippocampal atrophy occurs in Multiple Sclerosis (MS) patients since the early disease stages and has been associated with the impairment of episodic, visuospatial and verbal memory. Despite the growing clinical interest, Magnetic Resonance Imaging (MRI) derived measures of the hippocampal volume (HipV) from large datasets are missing, with important limitations for the implementation of this measure in large clinical studies.
Objective: To assess normative data of the HipV in healthy subjects (HS) on a large cross-sectional MRI dataset to be used as a reference in clinical studies.
Materials: The HipV of 727 HS was assessed from freely available MRI datasets. The age at scan-time ranged from 20 to 80 years. Data were stratified for gender and magnetic field strength (1.5 and 3 T). Volumes were obtained using a semi-automated approach, based on the manual editing of the masks obtained with FIRST (fsl.fmrib.ox.ac.uk/fsl/fslwiki/FIRST). In 100 MRI scans, the accuracy of the method was compared with a fully manual segmentation output and with the fully automated outputs from FIRST and FreeSurfer. Finally, a multivariate regression using HipV corrected for head size as dependent variable and gender and age and their interactions as predictors was performed.
Results: Volume masks from our semi-automated approach were very similar to those obtained with the fully manual approach (7.1±0.7 cm3 vs 7.1±0.6 cm3, p=0.98; DICE=0.92) and significantly lower than those obtained fully automatically with FreeSurfer (8.5±0.94 cm3, p< 0.001; DICE=0.8) and FIRST (8.2±0.83 cm3, p< 0.001; DICE=0.88). Age, quadratic age and gender were the predictors better fitting HipVs (R2=0.164, p< 0.001). Due to the dependence on gender, females showed constantly larger HipV with respect to males (0.44 cm3, p< 0.0001). Due to the dependence on age, HipV decreased by 0.07% per year between 25 and 55 years of age (Hip female at 25 years: 9.9 cm3; at 55 years: 9.7 cm3), with an apparent acceleration (0.51% per year) between 55 and 85 years of age (Hip female at 85 years: 8.2 cm3).
Discussion: The study provides normative data of HipV over the adult life-span for males and females to be used as reference in MS studies at group and individual levels.
Disclosure:
L. Luchetti, G. Gentile, M. Battaglini, A. Giorgio have nothing to declare
N. De Stefano has received honoraria from Biogen-Idec, Genzyme, Merck Serono, Novartis, Roche and Teva for consulting services, speaking and travel support. He serves on advisory boards for Merck Serono, Novartis, Biogen-Idec, Roche, and Genzyme, he has received research grant support from the Italian MS Society.