title: Comprehensive brain analysis with automated high-resolution magnetization transfer measurements.
abstract: OBJECTIVE
  To enhance the reliability and spatial resolution of magnetization transfer ratio (MTR) measurements for interrogation of subcortical brain regions with an automated volume of interest (VOI) approach.
  
  
  METHODS
  A 3D magnetization transfer (MT) sequence was acquired using a scan-rescan imaging protocol in nine healthy volunteers. VOI definition masks for the MTR measurements were generated using FreeSurfer and compared to a manual region of interest (ROI) approach. (The longitudinal stability of MTR was monitored using agar gel phantom over a 5-month period.) Intraclass correlation coefficients (ICCs), coefficients of variation (CVs), and instrumental standard deviation (ISD) were determined.
  
  
  RESULTS
  CVs ranged from 1.29%-2.64% (automated) vs. 1.30%-3.40% (manual). ISDs ranged from 0.62-1.10 pu (automated) vs. 0.68-1.67 pu (manual). The SD of the running difference was 1.70% for the phantom scans. The Bland-Altman method indicated interchangeability of the automated VOI and manual ROI measurements.
  
  
  CONCLUSIONS
  The automated VOI approach for MTR measurement yielded higher ICCs, lower CVs, and lower ISDs compared to the manual method, supporting the utility of this strategy. These results demonstrate the feasibility of obtaining reliable MTR measurements in hippocampus and other critical subcortical regions.
authors: Radiology, NorthShore University HealthSystem, Evanston, Illinois 60201, USA. YWu@northshore.org
authors: Ying
authors: Y
authors: Wu
authors: Hongyan
authors: H
authors: Du
authors: Pippa
authors: P
authors: Storey
authors: Christopher
authors: C
authors: Glielmi
authors: Fiona
authors: F
authors: Malone
authors: Shawn
authors: S
authors: Sidharthan
authors: Ann
authors: A
authors: Ragin
authors: Paul S
authors: PS
authors: Tofts
authors: Robert R
authors: RR
authors: Edelman
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results