Myocardial T measurements in iron‐overloaded thalassemia: An in vivo study to investigate optimal methods of quantification

Reproducible and accurate myocardial T measurements are required for the quantification of iron in heart tissue in transfused thalassemia. The aim of this study was to determine the best method to measure the myocardial T from multi‐gradient‐echo data acquired both with and without black‐blood preparation. Sixteen thalassemia patients from six centers were scanned twice locally, within 1 week, using an optimized bright‐blood T sequence and then subsequently scanned at the standardization center in London within 4 weeks, using a T sequence both with and without black‐blood preparation. Different curve‐fitting models (monoexponential, truncation, and offset) were applied to the data and the results were compared by means of reproducibility. T measurements obtained using the bright‐ and black‐blood techniques. The black‐blood data were well fitted by the monoexponential model, which suggests that a more accurate measure of T can be obtained by removing the main source of errors in the bright‐blood data. For bright‐blood data, the offset model appeared to underestimate T values substantially and was less reproducible. The truncation model gave rise to more reproducible T measurements, which were also closer to the values obtained from the black‐blood data. Magn Reson Med 60:1082–1089, 2008. © 2008 Wiley‐Liss, Inc.