title: MRI-derived measurements of human subcortical, ventricular and intracranial brain volumes: Reliability effects of scan sessions, acquisition sequences, data analyses, scanner upgrade, scanner vendors and field strengths.
abstract: Automated MRI-derived measurements of in-vivo human brain volumes provide novel insights into normal and abnormal neuroanatomy, but little is known about measurement reliability. Here we assess the impact of image acquisition variables (scan session, MRI sequence, scanner upgrade, vendor and field strengths), FreeSurfer segmentation pre-processing variables (image averaging, B1 field inhomogeneity correction) and segmentation analysis variables (probabilistic atlas) on resultant image segmentation volumes from older (n=15, mean age 69.5) and younger (both n=5, mean ages 34 and 36.5) healthy subjects. The variability between hippocampal, thalamic, caudate, putamen, lateral ventricular and total intracranial volume measures across sessions on the same scanner on different days is less than 4.3% for the older group and less than 2.3% for the younger group. Within-scanner measurements are remarkably reliable across scan sessions, being minimally affected by averaging of multiple acquisitions, B1 correction, acquisition sequence (MPRAGE vs. multi-echo-FLASH), major scanner upgrades (Sonata-Avanto, Trio-TrioTIM), and segmentation atlas (MPRAGE or multi-echo-FLASH). Volume measurements across platforms (Siemens Sonata vs. GE Signa) and field strengths (1.5 T vs. 3 T) result in a volume difference bias but with a comparable variance as that measured within-scanner, implying that multi-site studies may not necessarily require a much larger sample to detect a specific effect. These results suggest that volumes derived from automated segmentation of T1-weighted structural images are reliable measures within the same scanner platform, even after upgrades; however, combining data across platform and across field-strength introduces a bias that should be considered in the design of multi-site studies, such as clinical drug trials. The results derived from the young groups (scanner upgrade effects and B1 inhomogeneity correction effects) should be considered as preliminary and in need for further validation with a larger dataset.
authors.affiliation: Center for Mind-Brain Sciences, Department of Cognitive and Education Sciences, University of Trento, Italy. jorge.jovicich@unitn.it
authors.forename: Jorge
authors.initials: J
authors.lastname: Jovicich
authors.forename: Silvester
authors.initials: S
authors.lastname: Czanner
authors.forename: Xiao
authors.initials: X
authors.lastname: Han
authors.forename: David
authors.initials: D
authors.lastname: Salat
authors.forename: Andre
authors.initials: A
authors.lastname: van der Kouwe
authors.forename: Brian
authors.initials: B
authors.lastname: Quinn
authors.forename: Jenni
authors.initials: J
authors.lastname: Pacheco
authors.forename: Marilyn
authors.initials: M
authors.lastname: Albert
authors.forename: Ronald
authors.initials: R
authors.lastname: Killiany
authors.forename: Deborah
authors.initials: D
authors.lastname: Blacker
authors.forename: Paul
authors.initials: P
authors.lastname: Maguire
authors.forename: Diana
authors.initials: D
authors.lastname: Rosas
authors.forename: Nikos
authors.initials: N
authors.lastname: Makris
authors.forename: Randy
authors.initials: R
authors.lastname: Gollub
authors.forename: Anders
authors.initials: A
authors.lastname: Dale
authors.forename: Bradford C
authors.initials: BC
authors.lastname: Dickerson
authors.forename: Bruce
authors.initials: B
authors.lastname: Fischl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000033:anatomy & histology*; D001931:Brain Mapping / Q000295:instrumentation / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D015337:Multicenter Studies as Topic; D015203:Reproducibility of Results