Abstract

Reproducible and accurate myocardial Tmath image 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 Tmath image 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 Tmath image sequence and then subsequently scanned at the standardization center in London within 4 weeks, using a Tmath image 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. Tmath image 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 Tmath image 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 Tmath image values substantially and was less reproducible. The truncation model gave rise to more reproducible Tmath image measurements, which were also closer to the values obtained from the black-blood data.