PT - JOURNAL ARTICLE AU - Sormani, Maria P. AU - Iannucci, Giuseppe AU - Rocca, Maria A. AU - Mastronardo, Giovanna AU - Cercignani, Mara AU - Minicucci, Luca AU - Filippi, Massimo TI - Reproducibilty of Magnetization Transfer Ratio Histogram–Derived Measures of the Brainin Healthy Volunteers DP - 2000 Jan 01 TA - American Journal of Neuroradiology PG - 133--136 VI - 21 IP - 1 4099 - http://www.ajnr.org/content/21/1/133.short 4100 - http://www.ajnr.org/content/21/1/133.full SO - Am. J. Neuroradiol.2000 Jan 01; 21 AB - Summary: Using two MR scanners, we evaluated the intraobserver, interobserver, image-reimage, and interimager variabilities in the assessment of magnetization transfer ratio (MTR) histograms obtained monthly on four occasions from five healthy volunteers. With multiple observers, the mean coefficients of variations ranged from 2.2% to 8.2% for “pure” image-reimage variability, from 1.2% to 4.9% for interobserver variability, and from 2.1% to 4.9% for image-reimage variability. The mean intraobserver coefficients of variations were always lower than 1%. The mean coefficients of variations ranged from 10.2% to 14.6% for pure interimager variability and from 8.6% to 14.3% for interimager variability with multiple observers. Interimager variability accounted for 96.0% of the overall variability of average MTR, for 96.7% of peak location, and for 41.1% of the peak height. The use of different MR scanners is the main source of variability when obtaining MTR histograms.