He Taigang, Gatehouse Peter D, Smith Gillian C, Mohiaddin Raad H, Pennell Dudley J, Firmin David N
National Heart and Lung Institute, Imperial College London, London, UK.
Magn Reson Med. 2008 Nov;60(5):1082-9. doi: 10.1002/mrm.21744.
Reproducible and accurate myocardial T2* 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 T2* 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 T2* sequence and then subsequently scanned at the standardization center in London within 4 weeks, using a T2* 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. T2* 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 T2* 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 T2* values substantially and was less reproducible. The truncation model gave rise to more reproducible T2* measurements, which were also closer to the values obtained from the black-blood data.
对于输血性地中海贫血患者心脏组织中铁含量的定量分析，需要可重复且准确的心肌T2测量值。本研究的目的是确定从有和没有黑血准备的情况下采集的多梯度回波数据中测量心肌T2的最佳方法。来自六个中心的16名地中海贫血患者在当地1周内使用优化的亮血T2序列进行了两次扫描，随后在4周内于伦敦的标准化中心使用有和没有黑血准备的T2序列进行了扫描。将不同的曲线拟合模型（单指数、截断和偏移）应用于数据，并通过可重复性比较结果。使用亮血和黑血技术获得T2测量值。黑血数据通过单指数模型得到了很好的拟合，这表明通过去除亮血数据中的主要误差来源，可以获得更准确的T2测量值。对于亮血数据，偏移模型似乎大幅低估了T2值，且可重复性较差。截断模型产生的T2测量值更具可重复性，也更接近从黑血数据中获得的值。
