title: T1 and T2 measurements on a 1.5-T commercial MR imager.
abstract: In order for relaxation times to be used in clinical diagnosis, the precision of the measurement must be determined. The authors measured T1, T2, and proton density in a phantom and in human volunteers to determine the reproducibility of the method. The coefficient of variance of T1 measurements in the phantom during a 15-month period with two software upgrades was 5%. Variance of T2 measurements with any given software was 4% or less, and overall in the 15-month period, with two software changes, the T2 reproducibility was between 6% and 9%. The reproducibility is sufficiently high that precise clinical measurements of T1, T2, and proton density are feasible.
authors.affiliation: Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee 53226.
authors.forename: R K
authors.initials: RK
authors.lastname: Breger
authors.forename: A A
authors.initials: AA
authors.lastname: Rimm
authors.forename: M E
authors.initials: ME
authors.lastname: Fischer
authors.forename: R A
authors.initials: RA
authors.lastname: Papke
authors.forename: V M
authors.initials: VM
authors.lastname: Haughton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D008961:Models, Structural; D015203:Reproducibility of Results; D012984:Software; D013997:Time Factors