title: Errors in T1-determination using multislice technique and Gaussian slice profiles.
abstract: Multislice SE- or IR-sequences with different TR- and T1-times, respectively, are often used, to determine T1- and T2-values for tissue characterisation. To investigate the perturbating influence of the sequential excitation in multislice technique, we measured the signal intensities and calculated the T1-values of phantoms as a function of gap widths between neighboured slices. Phantoms contained fluids of different T1. We found a strong dependence of signal intensities and therefore of calculated T1-values on the gap width, when a T1/TR-ratio of more than 0.3-0.4 was reached. T1-values are considerably overestimated in this case, whereas T2-values are not influenced by the sequential excitation. We conclude that reliable T1-measurements necessitate a large spacing of more than 1 slice thickness between adjacent slices.
authors.affiliation: Fachbereich Kernspintomographie, Deutsche Klinik für Diagnostik, Wiesbaden, West Germany.
authors.forename: M
authors.initials: M
authors.lastname: Just
authors.forename: H P
authors.initials: HP
authors.lastname: Higer
authors.forename: P
authors.initials: P
authors.lastname: Pfannenstiel
mesh_terms: D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural