Ibrahim El-Sayed H, Rana Fauzia N, Johnson Kevin R, White Richard D
Department of Radiology, University of Florida College of Medicine, Jacksonville, Florida 32209, USA.
Hemoglobin. 2012;36(4):343-61. doi: 10.3109/03630269.2012.679376. Epub 2012 May 7.
Many patients with sickle cell disease receive blood transfusions as a life-saving treatment. However, excess transfusions may lead to increased body iron burden. Specifically, heart failure due to cardiac iron overload is the leading cause of death in these patients. The purpose of this study was to investigate the potential role of high-field 3.0-Tesla (T) cardiovascular magnetic resonance (CMR) for assessment of cardiac iron content by measuring the transverse relaxivity rate R2*. The R2* was measured in calibrated phantoms with different iron concentrations at 3.0T and 1.5T using optimized pulse sequences. Myocardial R2* was measured at 3.0T in a group of sickle cell disease patients with different disease stages, and the results were compared to the serum ferritin levels and hepatic R2*. The phantom R2* measurements at 3.0T were double those at 1.5T, and the measurements of both systems showed linear relationships with iron concentration. The 3.0T R2* was more sensitive than 1.5T in detecting low iron concentration. In patients, myocardial R2* had weak and good correlations with hepatic R2* and serum ferritin levels, respectively. Bland-Altman analysis showed low inter- and intra-observer variabilities. In conclusion, measuring myocardial R2* at 3.0T is a promising technique with high sensitivity and reproducibility for evaluating cardiac iron overload in sickle cell disease patients.
许多镰状细胞病患者接受输血作为一种挽救生命的治疗方法。然而,过量输血可能导致体内铁负荷增加。具体而言,心脏铁过载导致的心力衰竭是这些患者的主要死因。本研究的目的是通过测量横向弛豫率R2来研究高场3.0特斯拉(T)心血管磁共振(CMR)在评估心脏铁含量方面的潜在作用。使用优化的脉冲序列在3.0T和1.5T下对不同铁浓度的校准体模测量R2。在3.0T下对一组处于不同疾病阶段的镰状细胞病患者测量心肌R2*,并将结果与血清铁蛋白水平和肝脏R2进行比较。3.0T下体模的R2测量值是1.5T下的两倍,并且两个系统的测量值均与铁浓度呈线性关系。在检测低铁浓度时,3.0T的R2比1.5T更敏感。在患者中,心肌R2分别与肝脏R2和血清铁蛋白水平呈弱相关和良好相关。Bland-Altman分析显示观察者间和观察者内的变异性较低。总之,在3.0T下测量心肌R2是一种有前景的技术,对评估镰状细胞病患者的心脏铁过载具有高灵敏度和可重复性。